I would say that it depends on a number of things such as the number of rifles being sold by a particular dealer and what distributors he uses. Maybe buying bulk equals a discount. I have a good example:

My local dealer called Bushmaster when I was looking for a Dissipator. He [i]claims[/i] to only sell firearms for $20 over cost. He priced me the Dissipator at $792, which according to him means that he pays $772 for them. Well then, how come I found another dealer on the internet selling them brand new for $715? Either the out-of-state dealer gets a better deal on them than my local dealer, or my dealer is lying about how much profit he makes.