Mwave: http://www.mwave.com/mwave/SKUSearch_v3.asp?scriteria=AA75018
has a SEAGATE ST3500418AS Barracuda 7200.12 500GB 7200 RPM 16MB cache SATA
3.0Gb/s 3.5" internal hard drive for $39.99 with free shipping. If you have
a $5 review coupon it brings it down to 34.99.
New with 3 year warranty.