I'm an amateur game designer. I've built a story-driven game prototype. I've been struggling with freelance programmers for several months in my attempt to finish a demo to show potential crowdfunders - in order to finance real programmers to finish the game.
I just need a few scripts written and a bit of advice along the way. Why is that virtually impossible?
What i've seen in the past, is people building simple clickable-prototypes using something like InVisionApp or even using Keynote presentation software + http://keynotopia.com/ to build clickable demos within that. Hiring programmers to build out your prototype is tough since the low-cost will get you developers with not enough experience knowing how to build "just enough". And hiring expensive ass developers will get you a project that blows through your budget just coming up with a style-guide.
How we usually help people in your position is: build a very quick proposal of work done with time + cost, and then see what its going to take to get you in front of people to get more money to finish the build-out. It's just like buying a house: you can't get a mortgage unless you put a little something in first, to get the bank to help fund the rest of it.