[Canyonaro]

If it is written (the fax) and you agree with signing or orally, that is a contract. Once being a contract he is bound to that price. Now unless they could prove it as a contractual "mistake" (which in this case would be easy) then they are bound. From one of my law class books, "A unilateral mistake is where only one party to a contract is mistaken as to the terms or subject-matter. The courts will uphold such a contract unless it was determined that the non-mistaken party was aware of the mistake and tried to take advantage of the mistake." But this isn't say a house and you aren't getting the house at $100,000 when it is worth $300,000, so this mistake may not apply.

Either way you may not get that price, but you may get them to give you still a great deal.