The manufacturer refurbished Nook WiFi is marked down to $79 with free shipping on Barnes and Noble’s eBay store. It usually sells for $119 so that’s a pretty good discount.
It looks like the Nook WiFi will be at that price for six more days (Apr 12, 2011 02:00:28 PDT) or until they sell out.
The 3G model sells for $139 and it isn’t on sale like the WiFi model. B&N said they were going to stop making the 3G version back in January but so far they are still selling it both new and used.