Here's my estimate of part value. Subtract ~10% if you sell it all together.
Processor: Intel Core i7-940 $135
CPU Cooler: CORSAIR H50 $30
Motherboard: EVGA 141-BL-E757-TR X58 SLI LE $70
Memory: Patriot Gamer Series 4GB (2 x 2GB) $15
Hard Drive: Seagate Barracuda 7200.9 ST3500641AS 500GB $40
Optical Drive: Pioneer Black 5X BD-ROM $30
Optical Drive 2: 12X DVD±R DVD Burner $12
Power: ZALMAN ZM850-HP 850W $28
see review: http://www.hardwaresecrets.com/article/Zalman-ZM850-HP-Plus-Power-Supply-Review/1170/10
Case: Thermaltake V9 Black $40
I previously estimated the i7-940 at $150, but that's through eBay with all its hassle. Anyhow, you can see that some of my part estimates are low, but I don't think anything is too unreasonable. I also estimated the PSU at a higher value, but I have since read a review on it.