Is it cheaper to pre order or buy games

Games are preordered at full retail price, but may include bonuses. After a game's release you may find the game discounted and the longer after the release the more likely t will be cheaper than paying full retail.

As an example MW3 is being sold for preorder for full retail price and some small bonus items, but it will likely be available for 25% or more of a discount before the end of November 2011 for the Black Friday/Cyber Monday holiday sales. The same for Black Ops II this holiday season