My store only had 2 cards left. They were very difficult to find because they have prepaid cards, DLC cards, XBL Cards, etc in many different sections in the Video Game Dept.
I even asked someone in the dept before I found the cards and he didn't know what I was talking about.
It did ring up as $60 so I bought one.
Also, I checked my GamerClub membership on My.bestbuy.com and it already shows the 2 year extension.