The last box is $490 + ($20 shipping) at NewEgg. It looks like it has a nice set of features (e.g., DVD burner), but you might be able to do better.

I would not get the cheapest Acer you list - 256 MB of RAM is too little.

I've had good luck with refurbished Compaq machines. For nearly the same price as the last Acer machine, you can get [link|http://www.shopping.hp.com/webapp/shopping/product_detail.do?storeName=storefronts&landing=outlet_store&category=refurb_desktops&subcat1=compaq_presario&catLevel=4&product_code=EL445AAR%23ABA|this]:

Compaq Presario Media Center SR1750NX PC, refurbished
(EL445AAR#ABA)
\t\t
Price \t$499.99

AMD Athlon@ 3500+ processor with Enhanced Virus Protection; 2.2GHz
Windows XP Media Center
1.0GB DDR PC3200 SDRAM memory (2 x 512MB for ultimate performance); (expandable to 4GB)
Integrated ATI Radeon Xpress 200 Graphics with 256MB shared video memory
200GB 7200 rpm Serial ATA hard drive
LightScribe DVD\ufffdR/RW drive with CD writer capabilies and double layer support
Memory slots 4 DIMM (two available)
9-in-1 memory card reader, 3 USB 2.0 ports, 1 IEEE 1394 (FireWire) port, Microphone/line-in/line-out
10/100Base-T network interface
Integrated audio, 6-speaker configurable
15.35" (H) x 7.17" (W) x 16.54" (D) (unpackaged)

They occasionally have free shipping, but they don't mention it right now. This box has a much bigger hard drive, more RAM, a potentially faster processor, maybe a better DVD writer, but it has Integrated Graphics and uses shared memory (but the Acer may as well). In the detailed specs it says it has an Asus A8AE-LE motherboard; I can't find specs on the power supply. I don't know whether XP Media Center is a plus or minus... It comes with a boatload of software (much of which may be useless). It has a 90 day warranty.

Bottom line, the $500 Acer looks pretty good, but you can probably do better with some searching around.

Hope this helps. Good luck!

Cheers,
Scott.