I am posting this as a lara croft enthusiast and I know there are cheaper deals with these ones on PC, but if you want to play it on Xbox and you're with gold these are good deals.
Tomb Raider trilogy Going for A$7.50 (RRP A$39.95) each
Tomb Raider 2013: A$24.97 (RRP A$49.95)
Enslaved: A$6.58 (RRP A$19.95)
If yo're planning on buying the trilogy, you might consider buying at EB Games which sells it at A$18.00 (Pre-owned) which will be $3 cheaper