What do the miniatures look like? How much will they add?
Yeah, seriously. $30.
You're exchanging card board marker for plastic ships. At least you get to paint them? Beyond that I think that it simply makes the kickstarter look more attractive. Kickstarter + miniatures = untold riches.
I'm actually more concerned with - if I buy the minis now... Will the expansions have them too? Seems silly to buy a new expansion and have to use cardboard markers when you old game has all minis.
I have no fears that they'll miss the opportunity to sell more plastic figures when the time comes. That should be the least of your concerns.