Good read on Kickstarter and Card games over at Medium. This campaign seemed realistic about stretch goals and still lost money. I like their logic for tying stretch goals to backer count and not $ amount.
We made $142,000 on Kickstarter and you can too — Medium
https://medium.com/@contendergame/we-made-142-000-on-kickstarter-and-you-can-too-fbd9268e661f#.qlgeyakvn