Yeah, if it's not for gaming those budget Dells are nice for the money. They're practically giving you the LCD for free. If DOES have a PCI-E slot so you could also throw a budget video card in there. The factory PSU will handle a Radeon HD 3650 which Newegg has for $50.
Here's the link to that Dell $399 deal:
http://configure.us.dell.com/dellstore/ ... c=topic~us
If you want to build yourself, working within your tight budget and assuming you want to do some serious gaming, I came up with this:
Biostar Tforce TA790GX mobo, $110 ($100 after rebate)
http://www.newegg.com/Product/Product.a ... 6813138130
AMD Phenom 8650 Toliman 2.3GHz CPU, $88
http://www.newegg.com/Product/Product.a ... 6819103253
OCZ Platinum 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) $34
http://www.newegg.com/Product/Product.a ... 6820227178
*** NOTE: I never trust off the shelf RAM. I would instead recommend you order RAM specifically for this mobo from Crucial.com direct. Also, if you're running WinXP you could get away with 2Gb.
HIS Hightech H465FS512P Radeon HD 4650 512MB $55 ($45 after rebate)
http://www.newegg.com/Product/Product.a ... 6814161262
NOTE: Not a high end card by today's standards but equivalent (according to Tom' Hardware VGA charts) to a Geforce 8800GT which is no slouch. I was using an 8800GT up until 2 months ago and it played everything just fine.
Seagate Barracuda 7200.12 500GB 7200 RPM 16MB Cache SATA 3.0Gb/s HDD $60
http://www.newegg.com/Product/Product.a ... 6822148395
Rosewill RG530-2 530W 80Plus Bronze Certified PSU $60
http://www.newegg.com/Product/Product.a ... 6817182160
TOTAL $387
NOTE: I quoted this with 2Gb or RAM assuming you will install WinXP. If you go with Vista I would recommend 4Gb. RAM is pretty darn cheap anyway.