The unlocked iPhone 5 price is starting from $649 for 16GB iPhone 5; $749 for 32GB iPhone 5 and $849 for 64GB iPhone 5.
If you live in 3G only area in US and want an unlocked iPhone, iPhone 4S and iPhone 4 may be worth considering. Apple has been selling unlocked versions of 16GB iPhone 4S and 8GB iPhone 4. The 16GB unlocked iPhone 4S is priced at $545 and the 8GB unlocked iPhone 4S is priced at $450. The iPhone 4S and iPhone 4 uses a micro-SIM card.