How much is my computer worth ?

Well its 6 years old. With a 5 generation old vid card. Youd be lucky to get $200 for it.

If you have a local buyer, sell it as a unit, otherwise sell the CPU, MoBo, GPU, and RAM and save the rest for an upgrade because its nearly impossible to sell a case, psu, or hard drive and get a worth-while return individually.

As a unit I would ask $750 but take $300 or more.
In pieces you could probably get $200-300 like I said above, but you will have more work and probably eBay fees etc. I think you're Q6600 (i am guessing based on the link) may be in demand for the right crowd, as well as your GPU and RAM.

$200 sounds about right for that PC, since the C2Q is still of value to those who never ever upgrade.

$200 is spot on, as some posters above have said.

$300 would be good. It is still a lot better for gaming than a $300 dollar PC from Best Buy, it would be perfect for someone who wants to take the step from console to PC gaming, yet has a limited budget.

It would be worth more to me as a backup server than the $100 - $150 you might get for it

Rule of Thumb - Take your build cost and then subtract 10% for 1st week .... then 5% for each month of age for 6 months (60% value at this point) ... then 10% for every 6 months thereafter.

This topic has been moved from the section Systems to section Deals by Area51reopened

"Only worth what somebody else is willing to pay for it"

That system might be somewhat difficult to sell, I would just hang on to it and use it as a backup media system of some sorts. Selling a used computer, usually means the buyer has an idea about components for PCs, and will most likely not go over $200 as stated above.

The reason I want to sell it is because it's just now getting to the point where I can't play the newest games, this was my first build made from parts I got for free aside from the ram, case and psu pretty much. Was hoping to get $200 towards the $730 I'm going to need for my more modern build.

What's the price for the hard drive?

well it's not actually a build as much as pre-built  
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Ps. is it bad to go off topic ? xD