RAM for LTSP

I'm building a virtual "server farm" inside a big linux box. It will be
an LTSP server running normal Linux apps for the remotes PLUS several
instances of VMware 4.x for Linux hosting various OS's. Unfortunately,
VMware requires a fixed amount of RAM to be carved out for each guest
OS.

This means I need lots-o-ram.

Where is the cheapest place to buy ram?

...Kevin