Try newegg. Their prices were cheaper on the HD is was looking for but i did not order from them as 1) they were out of stock on the HD i wanted, and 2) they do not have a phone number for placing orders. With my billing and shipping addresses constantly changing/being different, it is nice just to talk to someone in via the phone, rather than try to figure out some websites cryptic forms.
Be careful you get a drive with the full written manufacturer's warranty, Maxtors should be 3 years and Seagates 5 years. The cheapest vendors are selling non-retail authorized "pulls" and OEM drives with none or 1 year warranty.