So far I've kept all my rares but that's mostly because I really don't have many. If I had a lot of them I would probably only keep 12 as most people seem to do so I could have 6 upped and 6 unupped. Usually that's my rule with all cards since I never know what I will want to try out later. I only sell cards if I'm really close to getting cards in my current decks upped.
