reality check, a full bis char, hell forbid you have 2 sets of armor on it and a few transmog pieces... will go for ~1k coins... now I'm not saying noone's gonna buy them ever,
but people are much much (MUCH!) more likely to make a char, boost it to 85 for a few coins, get a few bis pieces with some more coins and then play the game with... say 5part DS and a wep, then find a guild to casually raid with them to get the rest of the gear, stumble upon some pieces that never drop and donate for... shared boss hc ring and trink... and you've just spent ~300 coins over a few months, now that, for most people is how they play... you don't donate 1000 euros and go "hmmmm what am I going to do now"