The people who use jailbroken iphones, are these bought from the apple stores? or the gray market?

i am planning to get an iphone 4 from canada (locked) to save on money, and get it jailbroken in my country, a friend told me that the locked iphones from original apple stores are always bound by contract, and you would have to keep paying the monthly bill till the stipulated time of the contract is over...so basically by the time the contract time is over, u have paid the same amount as that of an unlocked phone so then if there isnt any savings here why would they jailbreak it?|||regular phones.|||No they're regular phones.