Anyway, I'm pretty steamed about it. I think when you make a deal, you need to stick to it. Even then I still would have matched the $850 but I didn't get a chance to
A contract requires offer, acceptance and consideration. You did not get to the consideration part and the seller owes it to himself to get the most out of any transaction. He would have lost $100 if he completed the sale to you and if he waited, there was the risk you might have backed out.
Early bird gets the worm.