I am very sorry to hear anyone takes a hit like that. Sure, you are selling the car to feed hungry kids. I believe that people can fall on hard times and have to sell their prized possesion. That sucks.

I do not believe I can sign a contract that says $100,000.00
when I MUST HAVE $140,000.00.
I can't hang around for five days and not check my contract.
I can't go to the block without my contract !!
As far as the buyer (dealer) being a man of his word, ..... please ! He sells used cars!! He is one of the many who take advantage of persons in this hobby (though he bought the car legally and fairly).
This is a sad fact of life.
This situation does not appear to be the auction house excercising their right to an advantage in a gray area.