I can't speak for anywhere else but I bought it off contract in UK. Think it cost me £250 ish. Still have the receipt somewhere and still have the phone.
It was only ever available on O2 and cost £269 with a new contract.
iPhone will be available in an 8GB model for £269 (inc VAT) and will work with either a PC or Mac. Three new great value iPhone tariffs will be available from O2 starting at £35
https://www.apple.com/uk/pr/library...O2-as-Exclusive-Carrier-for-iPhone-in-UK.html
They did sell them off cheaper when the 3G was released but I thought they also were on contract.