How much do you think this PC is worth

Maximum 75-80% of the combined part prices!

What you should be doing is cutting the worth of each part by about 25%-30% and possibly on some parts even half!

Sorry to say, but used computers lose a lot of their value.

Not familiar with the cost of these components in the UK (besides conversion of currency, not sure how much these are in terms of value). But I'm assuming you built this to make a little profit. Check the Dells and the HPs and see what they go for similarly spec'd and then try to undercut by a little. Over here, I'm guess-timating you could get $1350 for it.

Just a word of advice, don't sell it on ebay.uk. You'll have problems shipping the thing (without damage) and once you do, you risk buyer scam. What I mean is the person will receive you rig, say that you shipped them a box of bricks and force paypal to give them back your money. So you'll be out your rig and money.

Just becareful.

If you guys have anything like craigslist try that in your city.