512 is pretty much a stardard, anything less will not perform nearly at its optimal capabilities. Buy a stick of 256, or better yet 512 or 1024mb ram. 256 ddr will run roughly 30-40, you can find some good deals. 512 is a little more, but a lot worth it at 50-70. You will notice a huge performance boost right away, especially in DAW programs that use a lot of virtual memory.

Phil