For £250-300 you could buy a significant upgrade.
Don't buy more DDR2 RAM, that's putting old hardware in old hardware, what you want to do is to buy a completely new Mobo/CPU and RAM, which you can for quite a low amount of money these days.
You've got a choice, AMD or Intel. Intel are a little more expensive but overall faster, however in the mid-range and low-range you won't notice any difference and this is where AMD shine compared to intel. Vaue for performance is what you get from AMD.
AMD:
Motherboard: Gigabyte GA-MA785GT-UD3H AMD 785G (Socket AM3) PCI-Express DDR3 Motherboard
RAM: Corsair 4GB (2X2GB) DDR3 PC3-10666C9 1333MHz Dual Channel Kit (CMV4GX3M2A1333C9)
CPU:
AMD Phenom II X2 Dual Core 545 3.00GHz (Socket AM3) - Retail
Case: Antec 300 Three Hundred Ultimate Gaming Case - Black
With this build you've done two things straight away. You've firstly made your PC ALOT more futureproof, and secondly, ALOT faster especially in memory-hungry games like BF2/PR. The case will last you a while as long as you don't want a 'top of the range' graphics card, and it has excellent cooling for it's value. The Motherboard is AM3, which means that it's ready for an upgrade of a AM3 socket CPU in years to come, and instead of having to buy a completley new CPU, RAM, and Motherboard, you will only need to fork out on the CPU. The RAM is this case is perfect for you and you should notice a huge difference all across the board.
You said, 'once the money starts flowing' you'll build your own PC, how much do you reckon you will be able to spend on the build? because what I suggested is fantastic at just £270, but as they say, bigger budget is better
