That would be a case of fraud, very different story. Plus, I would not have made a deal, there would be no contract between myself and the vendor if I am not the person who bought.

My point remains that since from the moment when I press "I accept," from my side the deal is in place, it *has* to be the same for the other side. Either there is a contract or there is not. Cannot be the case that there are obligations for me but that there is none yet for the other party.

Other considerations such as fraud would be not about whether there is a contract in place but about whether it's a valid contract. And fraud is a different animal in that it is a criminal matter.