I've found a few around Philadelphia - a nice Centennial for $250
http://philadelphia.craigslist.org/art/4248210885.html
[ATTACH=CONFIG]452317[/ATTACH]
Someone that doesn't know it's a Featherweight, selling for $150
http://philadelphia.craigslist.org/atq/4232101643.html
[ATTACH=CONFIG]452318[/ATTACH]
And finally, a $135 mystery machine that could be a Featherweight
http://philadelphia.craigslist.org/for/4234256978.html
Ad text: singer sewing machine small & old - $135 (West Chester)
This is a very small singer sewing machine.. works fine...comes in small carry case. if posted...- it's available, so don't ask, is it available.!
Now I just have to convince my sisters to spend their vacation buying used sewing machines for me...