[yojo2]

Aerocool VP-450 and Chieftec GPA-400S8 (or 450/500W models if they aren't much more expensive) are cheapest PSUs worth buying as of now. At least in my country, it's hard to tell what might be available in Serbia for a decent price.

[lol232]

I can always order it, there is a shoopkeeper I know that can order from stuff anywhere so I can buy it from him, and if it IS Available in Serbia, it is definitely cheaper (I.E. Big Mac in Finland is 6 Euros, in Serbia it's 2, the Processor I mentioned costs 110 In Finland, in Serbia it's 74).
Okay, I'll be buying those stuff soon.
I'll start from Mobo and processor, then the GPU, then RAM then finally the PSU, once I buy all I'll be putting all of that in my PC. Thanks for your help!

[yojo2]

Mobo, CPU and RAM have to be bought all at once. You can't leave your current RAM for a while because it won't fit.

[lol232]

As I said, I will not unbox any of these untill I buy the PSU.
Also, is it okay, to do this:
Buy Mobo, Processor and RAM, then the GPU, not overclocking it,
then buy PSU later and start overclocking.

[yojo2]

Okay then, but the idea itself of buying stuff and not unboxing it till later seems kind of strange to me.

[lol232]

Okay, mate, thanks for all your help !
I will buy the Mobo, Processor and RAM First, then I'll buy the GPU and some time later I will buy the PSU.
And I changed my mind, it is stupid - I'll simply put them into my PC as soon as I buy them and get home.