Need Cheap Computer: Buy Gateway or Build My Own?

I'm trying to decide whether building my own computer would be more bang for the buck than buying a cheap offering from Gateway or Dell. (This computer will only be used for surfing the web). For about $400, I could get either of the systems below. Which system do you prefer and why?

Cheap System 1: Gateway DX430B

Processor Intel® Pentium Dual Core Processor E2140
Memory 1024MB 667MHz Dual-Channel DDR2 SDRAM (2-512MB modules)
Hard Drive 160GB 7200rpm Serial ATA II/300 hard drive w/ 8MB cache
Optical Drive 16x Super Multi Format Double Layer DVD-RW/DVD-RAM ±R / CD-R/RW
Chassis Gateway® 5-Bay uATX Case
Floppy Drive 15-in-1 Memory Card Reader
Motherboard Systemboard with Intel® G965 Chipset & 10/100 network
Power Supply 400-Watt Power Supply
Video Intel® Graphics Media Accelerator X3000 with Maximum 384MB Shared Memory (Dynamic Video Memory Technology)

Cheap System 2: Custom Build

Processor AMD Athlon 64 3200+
Memory Corsair XMS2 1GB DDR2-800
Hard Drive Seagate Barracuda 7200.10 80GB
Optical Drive Pioneer 18X DVD+/-RW
Chassis Antec NSK4480B
Motherboard ASUS M2NBP-VM CSM (socket AM2; Nvidia Quadro NVS 210S/ Nforce 430B))
Power Supply Antec 380W (incl. w/case)
Video Onboard GeForce 6 GPU
Audio Onboard ADI AD1986A
Media Reader Ultra Products MD2 5.25" bay (ULT33069)

I must say, Itotallybelieveyou comes through again. Man he's fast, efficient and good!

:-P The guy must be overclocked.

You Custom Build system has faster ram and better on board video get a better psu and an amd x2 cpu.

I'd say to build it yourself as well. Also, if your budget can handle it, switch to a AM2 5000+ Black Edition. For the money, its the best AMD CPU that can be gotten. As to buying or building, if you build it yourself, you'll learn a lot more about what makes the computer work, you'll probably have better quality control, and you'll be better prepared with knowledge when it comes time to upgrade anything.

This is all from Newegg

LITE-ON 20X DVD±R Black IDE Model DH-20A3P-08
Item #: N82E16827106079
$27.99

Western Digital Caviar SE WD1600AAJS 160GB 7200 RPM SATA 3.0Gb/s Hard Drive
Item #: N82E16822136075
$49.99

SUPER TALENT INT-AIN1-C All-in-one USB 2.0 Card Reader
Item #: N82E16820609198
$7.99

Team Elite 1GB (2 x 512MB) 240-Pin DDR2 SDRAM DDR2 800
Item #: N82E16820313018
$26.99

Microsoft Windows Vista Home Basic Upgrade
Item #: N82E16832116153
$69.99

Rosewill Black Steel ATX Mid Tower Computer Case
Item #: N82E16811147074

Rosewill RD400-2-DB ATX V2.2 400W Power Supply - Retail
Item #: N82E16817182021
-$8.00 Instant
-$10.00 Combo
$42.98

ASRock ALIVENF6G-VSTA AM2 NVIDIA GeForce 6100 or 6150SE / nForce 430 (Depend on the version) Micro ATX AMD Motherboard - Retail
Item #: N82E16813157108

AMD Athlon 64 X2 3800+ Windsor 2.0GHz Socket AM2 89W Processor Model ADA3800CUBOX - Retail
Item #: N82E16819103735
-$8.00 Combo
$112.98

Subtotal: $338.91
+shipping

AMD Athlon 64 X2 4000+ Brisbane 2.1GHz Socket AM2 65W Processor
http://www.newegg.com/product/prod [...] 6819103774
SILVERSTONE Strider SST-ST40F ATX12V 400W Power Supply w/active PFC
http://www.newegg.com/product/prod [...] 6817163104
Koutech IO-FPM220 3.5" Floppy Drive & Multi Card Reader
http://www.newegg.com/product/prod [...] 6813998514
GIGABYTE GA-M61SME-S2 AM2 NVIDIA GeForce 6100 Micro ATX AMD Motherboard
http://www.newegg.com/product/prod [...] 6813128045
Rosewill R804BK Black Steel ATX Mid Tower Computer Case with 300W 24pin ATX PSU
http://www.newegg.com/product/prod [...] 6811147024
CORSAIR ValueSelect 2GB (2 x 1GB) 240-Pin DDR2 667 (PC2 5300)
http://www.newegg.com/product/prod [...] 6820145098
Western Digital Caviar SE WD1600AAJS 160GB 7200 RPM 8MB Cache SATA 3.0Gb/s Hard Drive
http://www.newegg.com/product/prod [...] 6822136075
LITE-ON 20X DVD Burner included extra White bezel
http://www.newegg.com/product/prod [...] 6827106079
Total w/shipping = 370 USD -$20 Mail in rebate for the power supply = ~$350

That leaves enough room to upgrade the mobo, case, PSU, Hard drive, or anything else
If you get that I say spend it on one of these 2 things: an OS (XP home or Vista Basic your choice either is about $90)
OR
spend it on a DX10 video card so you can game a bit (for about $75 you can get either a HD 2400XT or an 8500GT) both will play any game out today, but at lower than max settings (in some cases LOW settings and resolution)

i say build your own as well.
you have more controll.
you will love the machine more.
on the otherhand, if you botch the build you are left ass-out-in-the-wind. though you will have better upgrade options, you can build a new machine in the shell of your old one (ain't ATX great?).
i had a gateway, and it was a great machine don't get me wrong, but it comes with built in limitations when viewed in comparison with something you can build yourself.
after my first build, only my wife will be getting factory built desktops.

Thanks for all the great responses! Dudes, I'm gettin' a Dell. I'll save the custom work for my gaming rig.