Where's the cheapest place to buy and iPhone 4 or 5?

I want to buy it without a plan or contract the budget is 250 dollars I'm considering eBay but I prefer it from a store if possible.

I bought mine at best buy but at the time it was on sale for $300 & it was this summer but you could always try eBay or amazon. And i don't think you could actually get an iphone 4 or 5 for $250 unless you buy a broken or used one on eBay.