LaunchBox Digital - an incubator around here - gives teams $20k I think, plus connections and other resources. $100k is lot of money to develop a product. It's certainly not unreasonable if the specs call for it. But as someone else said, they're going to get paid regardless, PLUS they want future revenue from the idea.
I think you should shop around some more, and I'd be interested in talking to you more about this. Contact me at mgkimsal@gmail.com - willing to consider a money/equity split, and probably not anywhere near a $100k deal. :)
Thanks! I'll try to get in touch with LaunchBox today.
I'll drop you an email and you can see what I've got so far.
So what is a fair split?
Can you build a prototype of it? Even in Excel or something to get the general logic worked out?
When you have a vision of a finished product, it seems like so much work to get there. But usually you can break it down and find steps you can take iteratively.
Mocking up the idea will show you more about its potential and how it should be executed once developers start working on it for real.
Before you continue, you should conduct focus groups with people who have knowledge of the subject area. Best of luck.
Yes, they get the 100k, but I would probably keep more equity that way. I was surprised at how genuinely excited they became as they realized their own need for the web level features. And, of course, they immediately took it mobile.
Keep pounding the streets to find your technical co-founder. Go to meetups and other events. It's just like dating.