Richard,
If you accept the assignment, it does not automatically mean that there is a predetermined value; in fact, it is pretty clear that the value opinion is not predetermined, since it will be you who offers the value opinion, and their actions are contingent upon your opinion.
HOWEVER, this type of assignment is fraught with danger for you. I had it happen to me, and after the very firt one, I began to refuse such assignments- on advice from my lawyer.
By accepting it, even if you are very clear that the lender is your client- not the broker or purchaser- a court still may deem that you have a responsiblity to both of those parties. After all, yoiu KNEW that they would rely upon the appraisal.
My advice on this is to advise the lender that you will not and cannot serve two masters. If the purchaser really wants to know if they are paying the correct price, let them hire you directly. IF your opinion of value suits them, they can choose to proceed with the purchase. In that case, the lender can order a second appraisal from you. Nothing says you cannot use the same data and even the same report, with minor changes- like client, intended use/users, etc. and charge less for the second one.
Of course, if your value opinion is not to their liking, they may just walk from the deal and then you got paid for one and the second one will not be ordered.
Actually ticks me off when the brokers do this. They are just CYAing, or have not earned the trust of the client. I have explained this to brokers over and over again. Finally, I just tell them to send me my check and then I will begin the work and that the appraisal cannot be used for mortgage lending purposes.
So now, they just foist the responsibility on to your shoulders, with all the legal ramifications that go along with it. Think the broker or buyer won't sue you if they do not like what you find? Think again.
Brad Ellis, IFA,RAA