I think: PMAGs are less than $15. GI mags even less. That damn thing is like $200.
If someone is selling them for $200 they are way over MSRP, I've been seeing them for $130 where I shop. But, since you mentioned Pmags, Magpul was suppose to be either designing or coming out with a similar quad stacked mag in either 50-60 rounds. I want to say it was 50 rounds and had the length of a 30rder, which was of interest to me since it didn't increase the length of the weapon but did give you more rounds. Haven't heard anything on them in a while though.