Probably not going to happen at $30. The Target $20 12 month card deal in October was the last time cards were reasonably priced. They're going for like 50 today on feeBay.
360s come w/ 3 free months of LIVE right out of the box. What you used to do was sign up for a new gamertag on your console, select silver and then it would give you your first month Gold status. 3 accounts= 3 months. Has anyone done this since the Kinect shenanigans/ price increases began this fall?
Don't give MS a CC number anymore, they took away online account management from xbox.com. The old auto renewal scam is back.