Vendors offer less on cards that you don't really want and more on the cards you really do. $5 = We don't really want this card $9 = We want this card, but are not crazy about it $13 = We are trying to use this card's buy price to show off our buy prices
Example: At my store, we have 20 copies of M20 Leyline of the Void. The card will continue to go down in price over the next few months and they aren't selling them quickly. You bring us a Leyline, we want to at least make an offer on it, but as more pile up offers goes down.
