Planet M.U.L.E.

Before any end of round buy/sell, reveal what the price ranges for each buy/sell will be, as well as the shortages and store supplies. It does no good to think you'll spend X on food and energy, sell only some minerals, and then find you need a lot more.

Run each one twice. Right now the fixed order affects value -- since energy comes last, you cannot sell energy to get money for other things. You cannot sell crysite to get money to buy smithore. You cannot sell food and buy any minerals.

Have some way for people to sell things, for money for other things.

** The real-time mule buy/sell system might actually work for a big multiple item buy/sell round. Just make it a lot faster to move around -- fast "up/down one", and fast "far left/far right".