To be fair, I think the carriers in the US are paying Apple huge money to stay exclusive. In Canada you can get an iPhone with any of the major carriers, and most of the smaller carriers with a variety of contracts. But yeah, there really isn't any "budget" option for iPhones unless you want to sign a contract. In which case they become pretty damn cheap for the hardware you're getting.
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http://soundcloud.com/thundersheep/lunatic-asylum
http://soundcloud.com/thundersheep/summer-rain