I think aspiring pinball makers with lousy business and marketing skills are the ones going down the tubes as collectors get better at sniffing them out.
I suspect future Kickstarter projects (and similar) will need to share their business plans up front, show significant personal investment (a prototype?) and plans for how they will achieve production to satisfy those pre-orders. A reputation of some kind will need to be established so designer and/or company can be checked out.