Why no retail Acc in Market to trade for WM chars/coins

Hey

I had a idea, why ist not possible to sell retail accs at market?
maybe some1 stop at retail and get back to bc like me and dont Need his r1 glad anymore or some1 have finished Progress in top 100 time and have nothing to do or more accounts or just a blue geared or Gold on Server xy why he cant sell or trade this for a warmane acc or char? or coins?
warmane can take maybe 50 coins for a Transfer like this so they have more Money to pay Servers and staff and we have a big new tradeplatform.
this are just some example there are much more Things to trade.

i would use this and trade mine for a top geared druid or priest, what would you trade if ist possible? are u one with millions of Gold or a fast leveler, Multiglad or Hero of the Horde, Progress Raider with BiS Gear or do u have a solid char to start, what would u trade and for what? just wondering. /discuss

hope im in the right Forum and pls excuse my english :D

greetz

Other than it will screw warmane if something like this happens blizzard will ban accounts that are traded.

not to mention, it would give blizzard a reason to come after warmane.