If you remove the gold auction house, kept gold strictly for repairs and such, you would remove one key ingredient that is going to ruin the value of items. Botters.
Put more emphasis on an ITEM based system. Where gold means nothing except to craft BoAs, repair, potions, etc. Make higher MPs drop ridiculous loot compared to lower mps (so that bots cant farm easy) so you can either trade items in game or put them on the RMAH and make actual money. Because there will be no 'buy gold" function, items will now have a chance to float around their true value, and not compared/watered down to the billions and trillions of gold floating around.
May seem like a crazy idea but if you think about it long enough you will understand how this could be a fix. Think about this, in d2 gold meant nothing. and the real money spent on 3rd party sites went to bots not players. RMAH money goes majority to players in d3.
Edit* This includes removing the "buy gold" function from the RMAH, so you guys are not confused.