Difference of plans between locked and unlocked iPhone?

I'm confused
In my country india there's only unlocked iPhone
So my question is if I buy a locked iPhone
What profit does apple get get by selling 700$ iPhone in 200$
And are the plans different for locked and unlocked iPhone
So that the cost fills up.
Please explain!

This is business

Unlocked phones can be used with any network worldwide… It accepts any sim card. So that is why you pay so much for it. For a planned iphone, it is locked to a particular net can only used with a plan from that network where you pay monthly etc. From this plan, the network makes back its money from selling you for so cheap. And it is not apple who locks the phones, it is the Telephone companies.