How much does this gaming rig cost?

I’m looking to pick up a new rig and I found some guy selling his rig, specs are:
Intel Core I5 2400
ASUS P8H61-M LE/CSM Motherboard
4GB of DDR 1333 RAM
Sapphire HD 6870 1GB
Seasonic 520 Watt Power Supply
Midtower Case
Seagate 7200.12 500GB Hard Drive
Ocz vertex plus 60GB ssd
Just wondering about how much would this rig cost, of course used and not for the retail price, but what is a fair offer? He hasn’t given me a price yet so I want to know what’s fair.
Answer #1
£450 at most second hand. Not all that great!
Answer #2
You could build one for under 800 USD, the specs aren’t that great for it to be costly.
Answer #3
Yeah I’m not looking to spend that much so I’m waiting on him to reply with a price on that rig, I’m sure it won’t be too bad, just want to know how much I should looking to spend on it.
Answer #4
You can get those exact parts for around ~$650 new. I wouldn’t pay more than $500 for it used.
Answer #5
i am in the process of building one with a
2500 i5 clocked at 3.3 ghz
8 gigs of ram
750gb hd
an msi mobo
750w psu
gtx 550 ti
under 750
so yea i would say betwenn 400-600 is decent anything over is just rape