The Windows 7 price is basically legit, but since everything else seems not to be legit, I'm not putting a lot of stock in that site.
Actually, I should mention that it is showing the retail packaging for Windows 7, but it's not specifying that they are actually selling an OEM copy (since one of the entries says Windows 7 Ultimate 32 bit - retail packages of course come with both 32 and 64 bit disks so the distinction of the software package being either 32 or 64 bit is not necessary). I know other, more reputable companies do the same, but given the prices shown on the site, it makes me think there is something more going on. It's not outright false advertising, but it is certainly misleading.