How much is a computer like this worth?

I found it on craigslist and was thinking of buying it. What do ya think its worth?

-Intel E8400 Core 2 Duo dual-core (best dual-core there is; fantastic for gaming and used the new 45nm technologies) oc'd @ 3.6 Ghz per core
-4gb G.Skill pc6400 DDR2 RAM 800 MHz, blue alluminum-plated
-Lanbox Lite computer case w/ dual side windows
-Rosewill 550w Power Supply (SLI Ready, blue dual LED fans)
-Asus DVD Burner
-Blue Orb II CPU Cooler
-G31 MicroATX motherboard
-VisionTek HD 4850 video / graphics card (twice as fast as ATI's previous top-of-the-line card!)
-250gb Barracuda @ 7200 RPM, 16mb cache, very fast
-Edimax Wireless-G Network Card, will allow downloads in excess of 2mbps (as fast as I've downloaded as of yet)
-Logitech G5 Laser Gaming Mouse (best gaming mouse there is...new...)
-Thermaltake Flare Mouse pad, BRAND SPANKIN' new(shiny blue LEDs!)
-Saitek Eclipse Keyboard (brand new, very nice LED silver gaming keyboard)
-Windows Vista Home Premium 64-Bit (brand new, with software included and a fresh install)
-Full versions of Photoshop CS3, Microsoft Office 2007 Professional, 3DMark Vantage Professional and multiple games will also be freshly installed if you want, which alone are worth well over $1000 but will be included for free...)