Is it cheaper to buy an iphone in the states or canada (no plan)?

I live in canada, so if it is cheaper to buy an iphone in the states, could i use it here?

IPhone with no plan is around $650-700 and is the equivalent to an iPod touch with Wi-Fi. One with a plan is $200 plus data, texting, and calling plan. ($45-100 a month.)

IPhone is cheapest in Canada, when compared to all the prices over the world.