Just upgraded to a new PC and I have my old one for sale. It is still a very good computer, purchased for around $3k back in 2009 and upgraded a few times along the way. I used PCpartpicker.com to list all of my components and when a price was not available, I searched on e-bay and took the average price.
PCPartPicker part list / Price breakdown by merchant
CPU: Intel Core i7-940 2.93Ghz Quad-Core Processor ($150.00)
CPU Cooler: Noctua NH-U12P SE2 54.4 CFM CPU Cooler ($49.99 @ NCIX US)
Motherboard: Asus P6T ATX LGA1366 Motherboard ($200.00)
Memory: Corsair XMS3 6GB (3 x 2GB) DDR3-1333 Memory ($71.98 @ NCIX US)
Video Card: XFX Radeon HD 6950 2GB Video Card (2-Way CrossFire) ($150.00)
Video Card: XFX Radeon HD 6950 2GB Video Card (2-Way CrossFire) ($150.00)
Case: Cooler Master HAF 932 ATX Full Tower Case ($159.99 @ TigerDirect)
Power Supply: Corsair Enthusiast 750W 80+ Certified ATX Power Supply ($50.00)
Optical Drive: LG BH14NS40 Blu-Ray/DVD/CD Writer ($40.00)
Sound Card: Creative Labs Sound Blaster X-Fi Xtreme Audio 24-bit 96 KHz Sound Card ($30.00)
Total: $1051.96
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-07-30 12:21 EDT-0400
The total is a combination of prices for brand new hardware and manually entered prices of used hardware (the CPU, GPUs, PSU, sound card, optical drive, motherboard). I would take $900.00 for it. I’m in no rush to sell.