And the conclusion; the equation for selling to the market in the rules section is wrong. The current equation being used is screwed up. The new equation (listed below) will be implemented upon the next sync.
Thats a skill penalty. The higher your skill, the lower the number, and the higher your sale price. So someone with trade skill of 0 has a .2 penalty to the sale price, while someone with a 5 trading skill has a 0 penalty. It makes sense if you look at it in a larger sense.