Start with a better retainer search, see how that goes [dev1019]

An auction house should be a last resort, if all else fails lets ruin our economy and make it very tough for players to make money off crafting.

Before that lets try some alternate solutions.

First there is a definite problem with commerce. No one really understands what others desire. With an auction house theres a sales history, this allows us an understanding of what is needed and judging by the history, how much. This alone I believe is the biggest thing missing from the market wards. This could easily be solved with a better retainer search. Not only will people understand what people need (because people can finally ask for what they need) but it will create a player to player quest system which in my head can be nothing but fun.

Now if it's market ward crashes that are the bigger problem, I have a solution for that that also doesn't require the sure end to any sort of rewarding economy for the players.
If we took the actual player to retainer interactions out of the process, we wouldn't need to worry about filling up the wards.
Basically just have it all done through an auction house type window. From here you can set up your retainer to sell and put it in whatever ward you wanted. Players could also use this window to buy from other retainers.
This would give all the convenience of an auction house without the problems (sales history).