So, this was an informal bid situation? I am thinking that it is. Otherwise, the rules of the auction site would or should put the amp in your hands IF you met the posted price and agreement had been made. Even if this is an informal sale situation, if you and the seller had agreed on the deal and he has backed out then that is one amp I would not pursue further. I would note the seller and never give them the time of day again. Bad ethics. Once an agreement is made, the deal is set in my part of the world. If the seller is pulling a fast one on you thinking you will come back with a higher offer, he may get to hold the amp for a while. In such a case don’t be surprised if he contacts you in the not too distant fixture to say that that buyer has backed out. If he does, the; your agreement with him is null and void, imho....and you are free to offer him say $1726.50USD. He might take it. Or he may have sold the ampmout from under you. Either way, his ethics are questionable, imho.