Around here you will pay significantly more than $100 for a clean one, unless you get real lucky. Basically, you can probably get one cheap but it will be a slow and difficult search, or you can find one fast and it will be expensive. So if you want the "easy" way to find one, then save a search on ebay and go for it.

I found this clean opaque blue Super Sport at Goodwill for $13. I have visited thrift stores hundreds of times this year (kind of a hobby), and have found about a dozen really good deals. Its not like they have deals like this every day....