It does on the PC currently as there is competition between stores. The amount of games that were full price at launch a couple of years back that I've picked up for sub £5 is huge. That changes when you look at games from only 1 shop (so valves own stuff, EA and Blizzard mostly,) and imagine it'd be the same on consoles where you'd have to buy direct from the console makers.
A brilliant tool for PC games is
www.IsThereAnyDeal.com. add games to a watchlist, set a target price or discount percentage and the site will email you when your conditions are met. It also compares price history (so tells you if a deal is the lowest price it's ever been sold for,) and supports pretty much all legitimate sites but ignores the grey CD Keys style ones.