That site kicks ASS!
The funny thing is that I think it was logical who originally posted the link to that site, a couple of months ago.
I even think that those numbers are skewed because SO MANY copies that are sold now are foreign and can be had for cheap.
Do they distinguish region on that site, or do they take everything as a whole?
No idea about that. And of course you shouldn't trust such a site 100% but atleast it gives an
indication as to what the price of an item is on eBay/Amazon/...
If you search for
Final Fantasy, you'll find that FF7 is listed at $57.50. Now I have no clue whether that's correct or not, but atleast you get the idea that you shouldn't be selling it for $5. So using it in that way, it can really help.