I've only been playing as a trader for a few weeks, but so far I've just seen a strange imbalance of supply and demand. There will be 10 sell offers going for 40 gold per 100 bushels, but 2 buy offers going for 20 gold per 100. There have been a few times that the prices will match up reasonably, and I'll make 10 gold here and there, but it seems like people aren't setting realistic prices.
It may just take time for an 'invisible hand of the market' to take shape. As long as people aren't using the market as a "rot-free zone" or some other meta-game trick, I'd imagine eventually people will start to balance things out.
