At Staples of all places, when a game's price ends in a seven (for example: $29.97) it apparently means it is a clearance item.
It seems to vary from store to store, but I got 50% off two games at a Calgary location after asking if the games I was going to buy were clearance items. At another location, they would not give me a discount.
Discounts seem to be applied at the discretion of whichever blue shirt is running the show at the time. Or maybe each store has their own policy... I dunno.