This is over your budget but it's a very very nice rig. Probably close to what I might build if I were doing it now (although I'd step up the video card to a 9800 GTX+ and probably the motherboard to a 750i chipset):
Update RAIDMAX SMILODON ATX-612WB Black 1.0mm SECC Steel ATX Mid Tower Foldout MB Computer Case - Retail
Model #:ATX-612WB
Item #:N82E16811156063
Return Policy:Standard Return Policy
In Stock
$89.99 -$10.00 Instant $79.99
Update GIGABYTE GA-EP45-UD3R LGA 775 Intel P45 ATX Intel Motherboard - Retail
Model #:GA-EP45-UD3R
Item #:N82E16813128359
Return Policy:Limited 30-Day Return Policy
In Stock
Mail-in Rebate
$119.99 $119.99
Update EVGA 512-P3-N975-AR GeForce 9800 GT 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Retail
Model #:512-P3-N975-AR
Item #:N82E16814130380
Return Policy:Limited 30-Day Return Policy
In Stock
Mail-in Rebate
$129.99 $129.99
Update PC Power & Cooling S61EPS 610W Continuous @ 40°C EPS12V SLI Certified CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Retail
Model #:S61EPS
Item #:N82E16817703005
Return Policy:Standard Return Policy
In Stock
Mail-in Rebate
$199.99 -$105.00 Instant $94.99
Update Intel Core 2 Duo E8400 Wolfdale 3.0GHz LGA 775 65W Dual-Core Processor Model BX80570E8400 - Retail
Model #:BX80570E8400
Item #:N82E16819115037
Return Policy:Processors (CPUs) Return Policy
In Stock
$164.99 $164.99
Update Kingston HyperX 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory Model KHX8500D2K2/2GNR - Retail
Model #:KHX8500D2K2/2GNR
Item #:N82E16820104044
Return Policy:Limited Non-Refundable 30-Day Return Policy
In Stock
$31.99 $31.99
Update Seagate Barracuda 7200.10 ST3250410AS 250GB 7200 RPM SATA 3.0Gb/s Hard Drive - OEM
Model #:ST3250410AS
Item #:N82E16822148262
Return Policy:Limited 30-Day Return Policy
In Stock
$54.99 $54.99
Update SAMSUNG 22X DVD±R DVD Burner with LightScribe Black SATA Model SH-S223Q - OEM
Model #:SH-S223Q
Item #:N82E16827151173
Return Policy:Limited 30-Day Return Policy
In Stock
$27.99 $27.99
Update Creative Sound Blaster X-Fi XtremeGamer 7.1 Channels PCI Interface Sound Card - Retail
Model #:70SB073A00000
Item #:N82E16829102006
Return Policy:Standard Return Policy
In Stock
$90.99 $90.99
Update Microsoft Windows XP Professional SP3 for System Builders - OEM
Model #:E85-05683
Item #:N82E16832116515
Return Policy:Software Return Policy
In Stock
$139.99 -$5.00 Instant $134.99
Subtotal: $930.90
There are $65 in mail-in rebates that would help offset shipping so this total would be close all-in.
If you want to cut the price you could easily save $30 on the case (there are a lot of good cases in the $50 range), $20 on the power supply (there's a $35 mail in rebate on this one which is a great deal on this PSU and this isn't an area to skimp), $50 on the operating system (getting XP Home) and $90 on the sound card (going with on-board sound) for a total price drop of $190 bringing the total to $740 plus shipping minus mail-in rebates (probably $800 all-in).