Just a heads up, it is much easier to get a good response here if you post up details of the project instead of just a link to a kickstarter project.
My suggestion, lower your goal to the cost of one pair of shoes. Why? You say you are trying to get people behind the idea, then the sooner you reach your goal, the better. Heck, you could probably then just have a friend/family member donate that cost and you’ll be at 100%. Since you make the shoes by hand, it shouldn’t be too hard to estimate cost.
Oh, and you should definitely figure out other sizes than a men’s 9. It shouldn’t be too hard with a little googling or even asking around.