I need memory

...remember you get what you pay for....especially when it comes to computer parts, too cheap and they can cause even minor system problems. Just my $0.02

 

I'd check with newegg.com. But like the previous poster said, you get what you pay for. Especially with memory, I wouldn't be too frugal with.

 

Check on Craigslist, you never now, you might find someone trying to unload some.
OWC generally has pretty cheap prices, and a lifetime warranty.
Unless your Dual 1.25 Ghz is an upgrade,
It's $30 for the 512 MB module if your Dual 1.25 Ghz is the Mirrored Drive Doors or the FW 800 model. It will cost you a bit more if you upgraded a Sawtooth, Quicksilver, DA, or Gigabit Ethernet model to a dual 1.25 Ghz.