New build or upgrade? help!

[lxseto93]

I'm upgrading my PC soon for black friday and I am quite confused on what to upgrade, if things will be compatible, and if it is worth it to upgrade.
first of all my current build is:
motherboard: evga nForce 780i
processor: Intel Core 2 Quad Q6600 2.4 GhZ with arctic cooling fan
graphics: evga GTX 260 896 MB DDR3
memory: 4GB(2x2) OCZ SLI RAM DDR2
hard drive: 500 GB western digital
power supply: 750 watt pc power and cooling
case: coolermaster CM690 nvidia edition
OS: windows vista ultimate 64 bit
I'm currently thinking of upgrading my mobo, cpu, graphics, and ram. right now I'm thinking of an i7 cpu(which one?), gtx 460, and 3x2 gb ddr3 ram. I'm clueless about what motherboard to get. so, any suggestions about those? my budget is ~500$
also, someone wants to buy my pc right for 400 bucks. Is that a good price? What is a good price?
if that happens, please give me some suggestions on a completely new build that's noticeably better than my current one for <1000$. thanks!

 

[batuchka]

You have to elaborate what u intend to use the machine for @@

 

[Twoboxer]

Actually, I think your system is arguably worth more than $400 . . . maybe as much as $75-$500 . . . so its no surprise you've got an offer for $400.

Batuchka is correct - we can't really recommend a path until you tell us what you want to do, but an excellent i5 750 tower for gaming at 1920 resolution can be had for $900 . . . which happens to equal your $500 budget + $400 sale.