Well I expect partly the low price on the Metallica disc is partly due to the fact that the record company is able to shift units in such copious amounts that they can sell it at a reduced price, but due to the massive sales it will yield they'll still make their dough.
I must come clean though. Initially after having heard only St. Anger and Frantic I gave the album a verbal pasting. I then saw it for that low, low price and thought what-the-hey, i'll give it a go.
Now I must say, I've listened to the album twice in the last 3 days and it's got some good stuff on it, and i'm still not that keen on the two previously mentioned tracks. Not willing to make any more comments than that at this stage.