Unity Price Question

I've got one simple question.

Im using unity to develop my game. If the game is "finished" . What happens? I want to distribute it on Itunes and Google Play.(let)s say I already Have my accounts with both of these companies.)

Must I pay 75 each month the game is on the stores? or I need only to pay as long as Im developing it?

Thanks for the support and if is there any cheaper license with unity? Im just an individual and don't think I can afford 75 a month...

Have a good one.