Is that your main system? Seems a little on the slow side. If your willing to pay out £50 for RAM might as well save up for a while and get a whole new system....Just built a system for someone (minus a graphics card, onboard will do for what they want) for £320. Includes AMD Athlon 64x2 6000+, 2GB ddr2 800mhz ram, 250GB hard drive, screen, mouse etc. Just an idea.
If not, ive got 2 sticks of DDR3200 sitting in an old broken PC I could send, think they are both 512mb, I know one is at least!