Obvious Troll is Obvious:

Give me a market system as broad and deep as EVE Online! I want my spreadsheets!

Forget having an AH or MW, we need market windows (read: counters) at every aetherite node! This way, you never have to go far to find one. Also, we would need the ability to buy from any other node's market (as long as they are within range)!

Oh, and an escrow system!