FWIW, I went into my TRU, and they had XBOX Live kits for $25. Included 12 months of service, headset, and a disc with Tetris Worlds (full), Mechwarrior (demo), and MotoGP (demo).
The other Live kits, with Crimson Skies or Mechwarrior (full) were still at their normal price of $69.99.