How about a feature that if a live order goes dead more than twice it is automatically canceled. As it is a user can place as many orders as he wants, one at every price point, and then go to his pool and change the names of his workers from: x.1, x.2, x.3... to x.a, x.b, x.c... this would make the worker appear dead. the user can then activate the worker at the best price point (by changing the name back to x.1)having it come back to life and bump the other users. if anyone places a bid at a higher price than the clever user he can simply activate the worker above the person who tried to outbid him.
this is what I believe is happening on the script market with the user with all of the 5.00 ghs limits (or it's a bot)