Just a heads up, there's a Square Enix sale on Xbox this week, and all the Tomb Raiders are on sale, as are most of their DLCs. Lara's Shadow is 74p, although for some weird reason Beneath the Ashes is not on sale
You can also get Challenge Pack 2 from GOL for 47p. I thought this one never came to the 360? The other Challenge Packs aren't on sale though annoyingly. Anyway I bought them.