Don't gamble your money.
There is no such thing a free lunch.
Most retailers have a 15%- 25% genuine mark up on products. ( Unless it's a chain supermarket demand up to 50% from suppliers) Always ask......How can they make money from this sale? If you can't figure that out then, they can't, so it's a bad call. Buyer Beware.
I'm surprised too! but in 3 years we have bought macs, laptops, software, and peripherals from them and they have been spot on. I think it possible helps having a Business Account and a having a good relationship with the guys in that dept. I would never buy a cheap PC from them tho!