That looks like quite an excellent deal. That's a unit for two controllers. I'm currently still using my original box of 40 Superstore generic brand batteries, they last for about the same amount of time as Duracell and Energizer.
I got it when it was first released from buy.com and used the Google checkout $10 off. It's really nice and the remotes charge pretty quickly. Plus the new battery covers are ridged and more rubberized.
Coo, I'll keep an eye out for a used one. When I can buy 48 batteries for $10 to last me a year it's not really worth it for a charging station IMO. But maybe if I can get it for $10 or less.....