Unsigned Estimates for a Contractor

Case: The defendant (=def) wanted to do major renovations in her home and asked the plaintiff (=pl), a contractor, for an estimate. After presenting a detailed price estimate, pl was chosen and began working; def never signed the estimate. During the course of the work, many changes were made to the original plan, without additional estimates being made. There is now a dispute over payment. Def feels that pl overcharged for many of the elements of the job and that she should not be bound by charges to which she never agreed. She feels this is true not only regarding the changes but even regarding some of the originally stated prices. She explains that this is why she did not sign the estimate. Pl says that not only is def bound by his price estimates, but since he can prove that the prices for the new elements of the job are his standard prices, she is bound by them since she did not ask for a new estimate. Additionally, some of the new elements were just additional units of work included in the original estimate.

Ruling: [Last week we saw that def is bound by the price estimate, and now we must look at the matter of the work that was decided upon after the estimate was set.]
The gemara (Bava Metzia 76a) deals with a middleman who told workers a price that the homeowner would pay where the homeowner had actually said a lower price. In such a case, where the worker was authorized to work but there was effectively no price set, the standard price is used and where there is a range, the worker receives the lower price (Shulchan Aruch, Choshen Mishpat 332:1). Therefore, regarding elements of the work whose price was not set, def ostensibly should only have to pay minimum prices.
However, there are exceptions to the rule. For example, the Rivash (475) and Rama (CM 333:8) discuss a chazan who was hired for a year with a certain compensation package. After the year, he continued working without discussing his compensation. They say that we assume that the same conditions continue. Therefore, in regard to elements of the work that are just additional units of items spelled out in the estimate, pl gets paid at the same rate.
The Maharashdam (CM 335) discusses a worker who did a job at a given price and after a few months did the same job without discussing price. The Maharashdam said that since prices in the field went up, the worker is entitled to a higher compensation. Furthermore, he says that if the worker previously received higher than average pay, he deserves more than average this time as well. Since the employer knew his price policy and agreed for him to work without stipulation, he accepted the policy upon himself. However, the Maharashdam concluded that since the worker is also at fault for not setting a new price, beit din should make a compromise between the different possible prices. Since the Maharashdam’s logic can be applied to our case, beit din asked of a court appointed expert to set a moderate price for those elements of the work that are not related to items in the original estimate.