Was your $87.50 returned?
A couple comments, its always the sellers perogative not to negotiiate, as well as to determine the shipping method. The seller can even decide that their first name is L.
However its as you say up to you as the buyer to decide to send the money or not-sounds like you saw some red flags and sent anyway. Always trust your gut.
The only issue I find here is that he accepted payment from multiple parties-not right. Other then that it sounds like he was being tough to deal with and wanted to set his own rules and have you follow them.
So if you got your money back-you're whole and you learned to trust your gut, and you gained some more experience on what guys are doing on the internet.
If your money is being held then thats another story......
Later.