"Sell limit must be higher than buy limit, obviously!"
Why, "obviously"? That's stupid. I want my markets to always buy food for 50 gold, and always sell it for 100 gold, as long as I have at least 600 bushels. But the game won't let me put an order to buy for a good sum when I have under a few K bushels (why can't I tell it to *always* buy?) and sell for a crazy sum when I have over 600. Reselling is pure profits, and everyone should be wanting to do something similar.