PLAINTIFF’S CROSS APPEAL
 Plaintiff contends the trial court erred in. concluding as a matter of law that she was not entitled to specific performance of the option agreement. We find no merit in this contention.
An option is not itself a contract to sell but is transformed into such a contract upon acceptance by the optionee in accordance with its terms. The contract then becomes specifically enforceable if it is otherwise a proper subject for such equitable relief. Kidd v. Early, 289 N.C. 343, 222 S.E. 2d 392 (1976); Byrd v. Freeman, 252 N.C. 724, 114 S.E. 2d 715 (1960). However, “[s]pecific performance does not follow as a matter of course merely from the establishment of the existence and validity of the contract involved, even though the contract is one in which the remedy is apposite. . . .” 12 Strong’s N.C. Index 3d, Specific Performance § 1, pp. 8-9.
In the instant case the court found that defendants were unable to convey good title to plaintiff as the land subject to the option was encumbered by a mortgage and a lappage. “Specific performance of a contract to convey land will not be decreed when the vendor cannot make a good title to the land sold, or when his title thereto is doubtful, Trimmer v. Gorman, 129 N.C., 161, 39 S.E., 804; Triplett v. Williams, 149 N.C., 394, 63 S.E., 79; 24 L.R.A., 514, and Thompson v. Power Co., 158 N.C., 587, 73 S.E., 888. . . .” Park, Inc. v. Brinn, 223 N.C. 502, 514, 27 S.E. 2d 548 (1943).
A purchaser may elect to take whatever title and quantity of land the vendor is able to convey and seek damages for any deficiency in his estate. Goldstein v. Trust Co., 241 N.C. 583, 86 S.E. 2d 84 (1955); Emerson v. Carras, 33 N.C. App. 91, 234 S.E. 2d 642 (1977). However, a purchaser may not specifically enforce a con*539tract in a method different from that which the contract specifies. Development Corp. v. Woodall, 21 N.C. App. 567, 205 S.E. 2d 592 (1974). See also McLean v. Keith, 236 N.C. 59, 72 S.E. 2d 44 (1952), 13 Strong’s N.C. Index 3d, Vendor and Purchaser § 5, p. 254.
Plaintiff did not elect to affirm the contract but chose instead to seek partial specific performance of it and demanded reduction in. the purchase price. She is not entitled to have the court rewrite the contract made by her with defendants. The record discloses no evidence from which the trier of fact could have determined a proper reduction in the purchase price or from which he might have assessed damages had the contract been affirmed.
We hold that in the absence of such evidence the trial judge properly denied specific performance.
Defendants contend first that the trial court erred in denying their motion for dismissal made at the close of plaintiff’s evidence. This contention has no merit.
G.S. 1A-1, Rule 41(b), provides in pertinent part:
. . . After the plaintiff, in an action tried by the court without a jury, has completed the presentation of his evidence, the defendant, without waiving his right to offer evidence in the event the motion is not granted, may move for a dismissal on the ground that upon the facts and the law the plaintiff has shown no right to relief. The court as trier of the facts may then determine them and render judgment against the plaintiff or may decline to render any judgment until the close of all the evidence. If the court renders judgment on the merits against the plaintiff, the court shall make findings as provided in Rule 52(a). . . .
 In a trial by the court without a jury, the judge is not compelled to find facts and pass upon a motion for dismissal at the close of plaintiff’s evidence. He may decline to render any judgment until all of the evidence is in, and, except in the clearest cases, he should follow that procedure. Helms v. Rea, 282 N.C. 610, 194 S.E. 2d 1 (1973).
*540  Defendants contend next that the court erred in refusing to admit testimony by the male defendant with respect to “the value of improvements, or lack of value of alleged improvements” made by plaintiff to the subject property. This contention has no merit.
At the time the trial judge refused to admit the testimony in question, he stated that the witness had not laid a proper foundation for the testimony. We think the testimony was properly excluded and for the reason stated by the trial judge. To place valuation testimony into evidence requires a proper foundation. At the minimum it must be shown that the witness is familiar with the thing on which he professes to put a value and that he possesses sufficient knowledge and experience to intelligently value it. Britt v. Smith, 6 N.C. App. 117, 169 S.E. 2d 482 (1969). Defendants failed to lay a foundation for the introduction of their valuation testimony.
Defendants contend the court erred in its finding of fact No. 11 for the reason the finding is not supported by the evidence. We find no merit in this contention.
The challenged finding relates primarily to conversations and transactions between the closing attorney and “defendants]’ a short while before the option period expired. Defendants argue that the evidence does not show that the feme defendant engaged in any conversation or transaction with the closing attorney on or about that date.
Technically, defendants’ argument is correct but finding No. 11 has to be considered in its relation to and as a part of the other findings of fact. In finding No. 15, to which defendants do not except, the court found that all times germane to this action, the male defendant was acting as agent for, and in concert with, the feme defendant who enjoyed the benefits derived from all payments made by plaintiff under the option agreement.
 Agency of the husband for his wife may be shown by evidence of facts and circumstances which authorize a reasonable inference that he was authorized to act for her. Lawing v. Jaynes, 20 N.C. App. 528, 202 S.E. 2d 334, rev. on other grounds 285 N.C. 418, 206 S.E. 2d 162 (1974). The wife’s retention of benefits from a contract negotiated by the husband is a factual circumstance giving rise to such an inference. Norburn v. Mackie, 262 N.C. 16, 136 *541S.E. 2d 279 (1964). Notice to and knowledge of an authorized agent is imputed to the principal even though the agent does not inform the principal thereof. 10 Strong’s N.C. Index 3d, Principal and Agent § 8. But the record in this case is replete with evidence that the feme defendant received notice that the closing attorney held plaintiff’s checks for defendants and that plaintiff was demanding delivery of a warranty deed from them.
Defendants contend the court erred in its findings of fact Nos. 16, 17 and 18 for the reason that said findings are not supported by the evidence. Suffice it to say, we have carefully reviewed the record and conclude that the findings are supported by the evidence.
Defendants contend that the court erred in entering the judgment awarding monetary damages to plaintiff for the reason that “plaintiff’s evidence and all the evidence established as a matter of law that the plaintiff was not entitled to the relief demanded”. They also contend that the findings of fact were not sufficient to support the conclusion of law “that plaintiff is entitled to recover the monies paid by her to defendants under the option contract and the value of the improvements made by her to the betterment of defendants’ land”.
 We hold that the trial court did not err in entering judgment in favor of plaintiff against defendants for $7,750, the sums paid by plaintiff under the option agreement. The record clearly shows that defendants’ title as to part of the land was in doubt. “If the vendor at the time fixed for conveyance is unable to convey the title stipulated for or implied by law, the vendee, if himself, ready, able, and willing to perform, may ordinarily elect to rescind and recover back amounts paid on the contract.” 77 Am. Jur. 2d, Vendor and Purchaser § 505, p. 632.
But we hold that the trial court did err in awarding plaintiff judgment for $5,000 purportedly representing “the value of improvements made by Plaintiff to the land owned by Defendants, all to the betterment thereof.”
While we have been unable to locate authority directly in point, we think the situation in Carter v. Carter, 182 N.C. 186, 108 S.E. 765 (1921), is analogous. In that case, the plaintiff entered upon the lands in question under a parol contract to convey. The *542owner refused to comply with the contract and pled the statute of frauds. The court restated the principle that in such cases the plaintiff is entitled to recover not only the purchase price paid by him, “but compensation for his improvements to the extent that they have enhanced the value of the land”. (Emphasis added.) Numerous cases are cited in Carter in support of the quoted principle.
Although defendants in the case at hand did not refuse absolutely to comply with their agreement as was the case in Carter, they in effect did so when they refused to work with plaintiff in removing the clouds from their title or in adjusting the purchase price to allow for the claim of a third party to the 16 acres in dispute.
It is true that the trial court concluded as a matter of law that plaintiff was entitled to recover “the value of the improvements made by her to the betterment of Defendants’ land” but this conclusion is not supported by a finding of fact. The finding that comes closest to supporting the conclusion is No. 18 which reads as follows:
18. That during the term of the option period, Plaintiff and her husband made and performed various work and improvements necessary to ready for their intended use the land owned by Defendants and the subject of said option contract, all with the knowledge and consent of Defendants; and that Plaintiff and her husband expended the sum of five thousand ($5,000.00) dollars therefor. (Emphasis ours.)
Thus it is clear that the trial court found that plaintiff spent $5,000 for work done on the land but never made any finding with respect to the extent that improvements made by plaintiff enhanced the value of the land. The increase in value of the land, rather than the sum of money expended is the proper measure of damages for these improvements. Carter, supra. For that reason, we hold that the part of the judgment awarding plaintiff $5,000 should be, and the same hereby is, set aside; and this cause is remanded to the district court for a new trial solely for the purpose of determining the amount that the improvements made by plaintiff enhanced the value of the land and entry of judgment based on that determination.
*543Affirmed in part, reversed in part and cause remanded.
Judges ARNOLD and ERWIN concur.