Microsoft's Major Nelson has listed a number of Xbox live Arcade titles that have been reduced to half price for the next week, exclusive to Xbox Live Gold members.
Running until July 4th, you'll be able to get Lara Croft and the Guardian of Light and Hard Corps: Uprising for 600MP (£5.14) each, while Comic Jumper, X-Men Arcade, Teenage Mutant Ninja Turtles: Turtles in Time Reshelled will each go for 400MP (£3.43).