From my investigations into the Star Citizen game.
The purchasing of the game is a one time deal.
So when you buy a game package then that is it, you get a full version, life time license.
This is NOT going to be like World of Warcraft with a monthly subscription fee. I personally hate those kind of games, which you need to pay an ongoing extortion for the privilege. Ha-Ha.
In Star Citizen you can buy a game package as cheap as $45 for a Aurora class ship which gives you a starter ship, a star flea equivalent and a Full Version Unlocked game.