Why do phone bills stay the same (when purchasing other mobile phones) even though the contract is over? e.g. if I pay for the iphone outright at Softbank I'm not paying monthly for my phone on top of my carrier bill. The phone bill is basically half of what it would be if i paid monthly for the iphone as well. [$40 if I pay $600 for the iPhone and about $80 if I choose to pay monthly for the iPhone]. With my current carrier KDDI, my 2 year contract finished ages ago but I'm still paying the same price that I paid when I signed up. Is that why people always upgrade after the contract is finished? Because for a new phone it's basically the same monthly bill? So really, one should always upgrade or pay cash upfront and upgrade? Also, since other carriers here don't have unlimited data plans, there's no point in buying an unlocked ip4 hey?. There's only one carrier that has unlimited data plans which is the same carrier that has the iPhone, Softbank. Unlocking the iP4 to use on another carrier wouldn't make any sense. Why do people care so much about unlocked iPhones if other carriers don't have unlimited data plans?