Well, it depends how far off your gig of RAM is. If it's a month or two, go with the 1 x 512 MB and just buy another stick when the funds come. If it's going to be a year, I would probably go with the 2 x 256. You could always sell them here on the forums when you're done. Right now it seems it wouldn't be a good idea to buy a socket 478 system anyway...