People are putting trading cards up for insane prices like £6, but they are not selling.
If you mouseover the graphs, it says how many cards were sold and for what price.
Only 2 RobbyZ cards were sold on the market, one went for only £0.04
If you want to sell your cards, don't sell them for moar than £0.50 ($0.80), even £0.50 is very expensive for a card.