I have two Kingston 512MB PC2100 SO-DIMMs available. These are Kingston p/n KTM-TP0028/512, and are equivalent to IBM p/n 10K0032. Although they are marketed for IBM ThinkPads, they are standard SO-DIMMs and should work in any system that uses this type of RAM. They were tested and work fine in a ThinkPad T-30, which is the only system I have access to in which they will work.
A quick scan of www.dealram.com info shows that the lowest prices for generic 512MB SO-DIMMs is $82/ea, and Kingston 512MB SO-DIMMs are $97/ea.
As I have no need for these, I will sell both DIMMs for $130 shipped anywhere in the US. They will come in the original packaging and of course have a lifetime warranty from Kingston. PayPal and USPS money orders accepted.