I think paying for beta is as close as we are going to get.
Kickstarter is also problematic since you need to define what the customer/investor is paying for before it's even in development or is a very basic prototype. In the world of flight sims where information about the sim you propose developing can be scarce of even impossible to obtain, it's better to leave the development until at such point the customer can make a decision where the level of detail is appropriate for them.
If ED did a kickstarter for a particular aircraft but in the end could not implement a feature because of lack info or other restriction a lot of players might be a tad annoyed, especially since being a simulator, by its definition, is a replica of the real thing to the highest degree possible, otherwise it would be called an approximator.
I would rather wait until theres a feasable demo or beta until I part my cash.