How should I go about upgrading?

I currently have:

ECS A780GM-A V1.0 MOBO

AMD Athlon 64 X2 6000+ CPU

4GB OCZ Gold 1066Mhz

Visiontek Radeon HD 5770 1GB GPU

Antec TP-750 750W PSU

 

I'm wondering if I should invest in upgrading the CPU, GPU, and RAM a little so that I can still play some more modern games while I save up for a better, more modern build, or if I should just stick it out and save up for a whole new build?

I have a friend that's looking to upgrade to an Intel I7 build and he said that I have first dibs on his current Phenom II X4 955.

My income is very limited.

I'm mostly looking for gaming performance, but I do like to play with CAD software, nothing fancy, and the occasional video editing.

 

Any help is greatly appreciated! : D

I always do an entirely new build but that's just a matter of personal preference.

I would love to, but I'm at square 1. I have no savings and almost no spendable income. 

My current rig can barely run any games that I'd like to play with friends. So it's basically do I continue to suffer alone until I can afford a new setup or do I upgrade my current rig a little to be able to play with friends and just deal with the longer wait to save up for a new rig? I did just acquire the STALKER series, so I have that going for me lol

See if you can get your friend to part with the am3 motherboard aswell (not something he can use for the i7 upgrade he is planning on anyway)
get 8 gb ram for the board, i suspect you will be needing ddr3 ram.

With your 5770 you should be able to run most modern games at alteast medium to high settings on 1080p.  
If you can get cpu/ram and motherboard very very cheap, you bought some time(about a year) to save up for the big computer upgrade that you will need in the future anyway.

 

Thank you! I didn't even think to ask about the MOBO.

Thanks for the input!