I think JNCS has a computer for $299.00
http://www.jncs.com/static-temp/sys-vp.php
256mb 512mb 1gb
Celeron 1.8 400FSB (OEM CPU) $299 $359 $469
Celeron 2.0 400FSB (OEM CPU) $319 $379 $489
Celeron D 2.4 533FSB (Retail CPU) $329 $389 $499
Celeron D 2.66 533FSB (Retail CPU) $349 $409 $519
Celeron D 2.8 533FSB (Retail CPU) $379 $439 $549
Celeron D 2.93 533FSB (Retail CPU) $399 $459 $569
Comes With:
Inwin L545P(Black) Thermally Advantaged Chassis with 240 Watt Power Supply
Intel D845GVFNL motherboard
Intel Celeron or Celeron 'D' CPU per above table
Kingston PC2700 Memory per above table
Seagate 40gb Hard Drive
Sony CD-ROM
Sony Black Floppy Drive
On-board 10/100 Network connector
USB 2.0 - 2 in back, 2 in front
On-board Video, 10/100 Network, Sound.
One Year JNCS Warranty
Note: No AGP slot - video cannot be upgraded.
Options:
$10 Substitute Asus P4SP-MX motherboard, has AGP 8x slot
$30 Upgrade to 52x/32x/52x Sony CDRW
$40 Upgrade to Sony Combo DVD Reader/CDRW
$25 Upgrade to Seagate 80gb Hard Drive
$60 Upgrade to Seagate 160gb Hard Drive
$129 Add Windows XP-Home, installed
$189 Add Windows XP-Pro, installed