use escrow. and LOL @ reverse engineer. The guy doesnt even really know which soft he has as shown when he says "i dunno it lets me flash any verifone" severely doubt he is a coder at all.
track2 was reseller for a long time anyways. His site was the most userfriendly and so easy to use and refund / ect.
He bought big bases, but not like guy had some super secret sweet dump supply. He would just buy giant bases and resell them.