A question on choices... What to do for my christmas upgrade?

I'm a University student, so I'm quite broke most of the time, but I'm planning to finally upgrade my pc again by christmas... I have the equivalent of about 500 US$, so here's my current setup (Stuff copied from speccy):

OS : Windows 7 Ultimate

CPU : Intel Core 2 Quad Q8400 @ 2.66GHz

RAM : 4.00 GB Dual-Channel DDR2 @ 401MHz (5-5-5-18)

MotherBoard : XFX MI-G31I-CH79 (CPU1)

Graphics :512MB GeForce 9800 GT (XFX Pine Group)

Storage : 932GB SAMSUNG HD103SI ATA Device (SATA)

               466GB Western Digital WDC WD5000AADS-00L4B1 ATA Device (SATA)

               1863GB Hitachi HDS722020ALA330 ATA Device (SATA)

 

So what do you guys think?

Edit:

I will mostly use it for gaming.

http://pcpartpicker.com/p/mtuU

Der, A little over budget, if that is a huge issue let me know

Thats your best bet though

Oops not a Z77 board.... fixed

http://pcpartpicker.com/p/mtvO

Thanks alot... While I won't be able to use US merchants (as I'm from South Africa) our prices are pretty much equivalent, except for graphics cards, so my main problem was choosing between :

Intel Ivybridge Core i5-3570K (3.4GHz Quad Core) (Unlocked)

and

Intel Ivybridge Core i7-3770 (3.4GHz Quad Core)

also I can get about 75 - 125 US$ for my old parts if I slap them into an old case I've got standing around...

Edit:

forgot to add that the price difference is about 80US$

You don't need an i7 for gaming an i5 will give you about the same preformance in gaming.

Yeah, that's what I thought, just wanted to be sure... Thanks alot for the input