2GB or 3GB? (RAM)

Sorry don't see this as expensive.

4 GB

And that's if you have to buy all 4 Gig

I checked my receipts.
I bought my 4GB (well it wasn't as fast as that, but) few yeras ago for ~60$ and the link you showed says 140$. So it's no where near dirty cheap.

That's why I showed some of the faster memory and you do understand that is $140.00 USD for all four gig. That's $35 US per gig and yeah I consider that cheap.

Unless you overclock your processor its not beneficial to get high performance memory. High performance memory is there so you don't have to put in a divider on the memory which causes it to be out of sync with your processor thus reducing the memory's performance. The increased bus frequency from overclocking would push normal memory past its limits and cause errors unless it had that divider set to a lower setting.

If I were you, I'd just check places like memory.com, kingston.com, or crucial.com and see what they suggest you put in your system.

edit:
checked, I guess 3 is enough for it... 2.5 it says really

There are a shortage of memory chips at the moment so if you buy now you will be paying allot more than you need

I would get 3GB. Memory is cheap these days so it doesn't hurt to get the extra power.