When I originally bought them, they were around $20-something a piece (this was almost 10 years ago, mind you).
I recall looking on Amazon once, and I found them but for something like $70. Way too much. That, and their status was "currently unavailable."
I haven't looked them up on eBay yet. I would imagine some sort of search for "storage tote" or "container" or whatever combination you would use to describe it would bring up the item or items just like it.
EDIT: just typed in a quick search for "plastic foot locker" and these suckers came up.
http://www.ebay.com/itm/Sterilite-1...5&pid=100005&rk=2&rkt=6&sd=232018119257&rt=nc
Price is right, it's basically the same one I used, and this particular link has a few available. Some others are up for auction, but I'd imagine there won't be anyone with a massive lot to sell. Hope this helps!