I don't think high grade common cards are rare because if you need an example of the card to complete a set you can easily get one. I think a card is rare if it is very difficult to find one to acquire in any condition. I prefer to have common cards in common conditions. What interests me most are cards that are very, very hard to find in any condition. Cards that have only a handful (or even one) specimen are the tops for me. I'll take this over a mint common Exhibit any day of the week:
