They sold out. So maybe the price was about right?
The 5970 is a very reliable card. 90% of them, including these ones, are reference designs and are identical.
Now what happens to the 5970 more often then other cards is they are damaged by overclocking. Putting two GPU's in a small space creates heat. Now from the factory, even ran 24x7 with proper cooling, they still are very reliable. You could probably run them for three years standard clocks, standard settings (like auto fan control). Add in overclocking and tweaking and everything changes. They overheat and dry out their thermal paste. Some run the fans maxed out which takes down their life dramatically.
It is very simple, treat them right and they will keep running.