01 Mar 2010 at 07:38 - 2
Uhhhh... really? Instead of giving you a meal, I'll teach you to fish. The price of all commodities available from the trader is traditionally the average of buy and sell price at the trader. In large quantities, such as 12e = 100k, it's slightly negotiable, but all sales are based on the average figure.
Instead of going to the trader and checking for you, I'll let you get some practice!