1. A customer who discovers, within the time span necessary to ascertain the true value of the article (and return to the proprietor), that he or she paid more than 16% of the fair market value , may generally rescind on the sale and demand a refund [Choshen Mishpat 227: 2].
2. A customer who discovers, within the time span necessary to ascertain the true value of the article (and return to the proprietor), that he or she paid 16% more than the fair market value , may not rescind on the sale, but may demand a refund for the additional 16%.
3. A seller is prohibited from taking advantage of a customer by deceivingly overcharging 16% or more than the fair market value for the sale or rental of real estate as by moveable objects.
4. Nevertheless, the Torah excludes real estate transactions from some significant guidelines of the prohibition.
Rema opines that a buyer/renter of real estate may only rescind on the transaction upon the discovery of being deceivingly overcharged more than 100% of the fair market value. Whereas, Shulchan Aruch maintains that the buyer is left with no recourse regardless of the extent of deceit .
As valid arguments can be made to both sides, we would respect the status quo [Choshen Mishpat 227: 29, Sha"ch 51].
5. After the time span necessary to ascertain the true value of the article (and return to the proprietor, the customer forfeits this right to retract on the deal. We assume that the customer ascertained the value, pardons the proprietor and consents to having been overcharged [Choshen Mishpat 227: 7].
6. A consumer who noticed an unforeseeable blemish after the transaction was completed, is entitled to recourse ad infinitum provided the consumer does not subsequently utilize the article. Otherwise, usage of the article indicates a consent to the deal [Choshen Mishpat 232: 3 Pischei Teshuva 1].
7. Similarly, a consumer who realized he/she was overcharged more than 16% and was unable to return to the seller immediately, loses the right to rescind by subsequently using the purchase [Nesivos 232: 5].
8. Is a consumer who has not yet paid in full likely to consent to the degree of overcharge after the time span necessary to ascertain the true value of the article, or does he/she view their holding on the money as leverage through which he/she can use to ensure a fair price as long as he/she still is in possession of the money? [Ketzos HaChoshen 227: 3]
As valid arguments can be made to both sides, we would respect the status quo, and would not obligate the consumer to continue paying the full agreed upon price.
Similarly, using the article would not indicate a consent to the sale price as long as the customer remains in possession of some of the funds [ Pischei Teshuva 227: 2].
Application
Leon transgressed the prohibition of deceitfully overcharging David. Leon overcharged David more than 100% of the fair market value. David's right for to rescind is subject to debate and we would respect the status quo. If David had paid in full, David would have no recourse.
David waited until the end of his rental to take up the issue. Additionally, he used the flat for the duration of the time. Generally, such behavior indicates consent to the initial terms and David's should have forfeited his claim against Leon. Nevertheless, as he retained possession of the remainder of the funds, his usage as well as his procrastination did not signify a consent to the initial terms. In addition, we would respect the status quo and not require David to pay more than the fair market value.
