I have played a few P2P mmo's. FFXI, Aion(before it went F2P), SWTOR (same as Aion),
Elder Scrolls Online, etc. Most of these games don't last long as they stand to make more money with some kind of cash shop option, and end up doing the same thing the RMT's do to an extent. I can't think of another MMO that didn't have a huge RMT problem. (Can't speak to WoW)