The Amazon prices are simply what the independent dealers that list on Amazon are asking-they fluctuate wildly, sometimes from day to day-

Last year, I lost my DVD of "Yellow Submarine", which I'd purchased new at Border's for $13, and blithely went to Amazon, where I figured I could pick up another for a similar sum--Big Surprise! It had gone out of print, and, since demand was high (or so I assume), the only copy available was $450! A few days later, some other dealers were offering copies for considerably less ($30-70), but I waited, an it's been re-released, and I got it for $12--

The short story is that those prices don't mean much--