What do you plan on doing with this computer, for 1800, you can get a very good system. Also, I recommend whating until mid-March, as the new ATI card should be out and lower the prices of the current video card market
If I had $1800 to spend, (minus the monitor) here is what I would get:
Case: Lian-Li PC-70 USB Aluminum ATX FULL tower case $240
MB: Gigabyte GA-7VRXP AMD XP Via333 MB with RAID ~$115-150.
CPU: AMD ATHLON XP 2000+/266 FSB PROCESSOR CPU - RETAIL BOX $260.00
Memory: 512 MB Kingston DDR 2100 SD RAM $150
Video Card: ATI Radeon AIW 8500-D $306
DVDROM: TOSHIBA INTERNAL DVD ROM, 16X DVD, 48X CD ROM $58.00
CDRW: TDK 32X/10X/40X INT EIDE CD-RW $160
Sparkle 400 Watt PS $85.00
(3) 40GB Maxtor ATA 133 7200RPM HD $261
Creative Labs Sound Blaster Audigy Platinum Retail Box $170
Keyboard, mouse and all other Mis. items with the remaining Cash.
Most of these prices are from Newegg.com and include shipping costs.
If it works for you then don't fix it.