I've noticed that some people on E-bay will sometimes put an uncommon or common card up for sale, then advertise it as "rare." I think that they believe that these cards are really hard to get a hold of *giggle*, and therefore, are rare finds. *snicker* Either that, or they're just trying to con money out of people, but they usually aren't successful in this.
I'm keeping a list of prices that cards are going for on E-bay, just for future reference.