Good place to buy an iphone 4s w/out a contract under $300?

I really want an iphone 4s for Christmas but my family has a no-contract phone service where you have to but your own phones. I've tried ebay and they're pretty expensive. A good-condition used one is ok.

In ratio shack

Iphone 4s No-contract
Source(s):
http://www.amazon.com/...y110171-20