Looking to upgrade - opinion on price and quality of system

I am looking to upgrade my current gaming system, which is quite old.

I know a guy that is selling a system with the following specs, and the system was built only a few months ago. He is needing to sell the system due to financial reasons and is askig $850.00 for the system.

Is this a fair price for the following system:

CPU - i5-2500k 3.3-3.8GHz
CPU Cooler - CM Hyper 212+
GPU - MSI Radeon 6950 2GB
RAM - 8GB Corsair XMS3 1333
Mobo - AsRock H67 (B3) w/ SATA6.0GB/s & USB3.0
Case - CM 690 Advanced II
HDD - Samsung Spinpoint F3 7200RPM 1TB
PSU - Corsair TX650
OS - Windows 7 Home Premium 64-bit
Wireless adapter - Premiertek Hermes PL18N


Any input would be appreciated.

Thanks,

TR