Memphis Car Audio

My friend has these subs and an amp. It's made by Memphis. Are they a good reliable brand. I never heard of them until he told me about them. He claims one 12" sub is like 130-150 bucks. He is selling his system. He wants like about 400 to 500 bucks for it. It has 2 12" subs, sub box, a 700 some watt amp (I aint sure how big it is it), and a compacitor and its all Memphis. Is it worth it