People give negative feedback when it is deserved.
If you can work things out, then why give negative feedback? People just want their games or their money or whatever. In this case it sounds like more than one market rule was not on the table anyway (a conversion, actually in your possession). At some point you have to be aware as a buyer too, particularly if you're attempting to buy something that unusual. I think as long as the buyer gets his item within a reasonable period of time or at least there's some decent communication on the delay and a chance to opt-out, that's alright.
Look down the ratings, you'll find that people who have negatives are real scammers. That's the important thing. No one who buys trades or sells on this forum regularly is here to rip you off.
