At this moment it does not seem like there is going to be a monthly purchase. The game is being developed as we speak and its expensive because the developers need a little bit of help with such a big game. Contribute as you wish, all the information on the packages you can buy should be on the main website. Currently the game is not even in it’s alpha stage.
@Lukas, they just recently added a news article at the bottom of their page talking about the first milestone unlocked, in the article they stated that they should be sending out the option to vote tomorrow, most likely via email.
