It's restrictive, but it's not as bad as it sounds. Sale prices are still respected, so long as they're not in artificially limited quantities or for specific times of day. That sounds like it's excluding things like "8 at this price" and Amazon lightning deals. I would assume, for example, if you bought a MacBook Pro from them, and Apple then has a Black Friday sale (which no special time or quantity limits), it would be eligible for the price guarantee.