Just an update. I was able to buy a used iPhone 3g, 8gb unit via craigslist.
This one is from December 2008, looks pretty chewed up. Screen has 2 short scratches about 30mm long and several other shorter scratches and the back looks like it's been through the meat grinder. I'm exaggerating of course, but I never let my stuff get this scratched up! Quite a few nicks and evidence of impacts from keys and other objects hitting it in a pocket.