We're already seeing a lot of price variation for new AAA titles: Resident Evil 6 - $39.99 Far Cry 3 - $49.99 Tomb Raider - $49.99 Bioshock: Infinite - $59.99 Company of Heroes 2 - $59.99
I agree that probably only CoD can push it up to $70. Not even BF4 will try that price without CoD going there first. There has been some attempts at charging higher prices a la Deluxe Editions, etc. I'm sure companies are using that data to figure out the minimum price they can charge.