Obviously the guy is just having a hissy fit because he has realised (and undoubtedly not for the first time) that he really doesn’t know his job properly and that HE missed the potential. You have to wonder if he ever pointed out to his clients (the Vendors) that they could have done this and reaped the benefits; also why he didn’t identify this as being a reason to try for a better price for his vendors; why did he not point out to you (and other buyers) the possbilities; why did he think that you, with whom he had no contract, should pay him anything at all?; the list goes on but what is the point of arguing with someone like this? I hope you just smiled sweetly and sold him a copy of your book! – majicjac