How much equity would you put on the table and how much money would you want for it? Keep in mind that if you have a good pitch you can bring in $1,000,000 for no equity and if your game is successful it could bring in another $3,000,000 to $10,000,000.
Also, it requires that you have a (typically consumer) product that you can pre-sell. What if you are making a Saas that could turn into a profitable business but that cannot be launched on Kickstarter? It might still be a good investment opportunity so the other model could work.
I wonder what fair numbers would be. Hrm. Hard to say. A lot of 1-4 man small teams would do it on second thought. I think $100k for 10% is a pretty crap deal but creators would probably take that offer. Hard to know how Joe Public would respond. Definitely hard to predict after 5 years when people compile lists of games that even gave a break even return. Game companies and software startups don't exactly have a high success rate.