Sadly, too many people see only the good side of ebay selling - so much so that they don't read or understand the fees involved. One of the reasons I quit selling stuff on ebay over 10 years ago - just too much drama and BS, having to deal with the "ifs, ands, and buts" of it all. And the fees they charge are ridiculous. I'm all for making a profit but jeeeeeees, sometime it's a bit much. But then, noboby's making anyone use 'em either.
I tried on a couple of occasions to make side deals and it seemed every time I did, it degraded to a pissin' match. Best advice - "buyer beware, seller beware".
Just part of doing ebay. IMO.