User blog comment:PuffPastry/Card Value ≠ PP/@comment-5706972-20130205210556

The bottom line is that the value is the value - but how people are willing to pay for it differs. Most people will pay 2pp or another card valued at 2pp equally, but not everybody has 2500pp lying around to buy a top card, so they will trade other cards for it or want to pay a reduced rate for giving up precious potion inventory.