I like the exchange, but I wish people had more of an idea of how to price things, people often price things and WAY more then cost. I try to price my things around cost or slightly below.
"Cost" is completely arbitrary, though, for items that can't be bought from a vendor. The value of an item is completely dependant on what someone's willing to pay for the convenience of not having to go out and farm it. I can easily sell mid-range food to tribble breeders for 1,000-2,000 credits a pop. Should I really settle for 40 credits, because that's the worth the game's assigned to it?