I think i picked up my last 1gb SD card for around $60 USD.
If your thinking about maybe getting a CF card for expansion, check out the Hitachi (formerly IBM) MicroDrives. They are hardrives that are the size of your standard CF card and go into just about all CF card slots. Not to mention you can get the 4gb model for $151.25 USD from newegg.com.
http://shopper.cnet.com/Hitachi_Micr...-31315314.html
Theres a 2gb model, which is about $50 less.
http://shopper.cnet.com/Hitachi_Micr...-30979283.html
I just wish my Axim x30 had a CF slot, so that I could use these!