Thanks for your comment. I think 20% is a fair price for idea/validation/first sell and direct access to a customer space. If it's going to be a $100m company in 2 years then yes, 20% is going to hurt, but honestly I don't expect that.
Maybe not hurt if it was not dilutable, the initial 20% holder could be issued more shares to keep their percentage at 20%. By the time 3 or 4 rounds are raised the initial 80% owner might only retain 20% after dilution. So in the end you have to look at the cap table after future rounds, the fact that during a period of history (probably before there is any real cash to distribute) the split was 80/20 won't matter.
But more importantly, if I build the product and get the first customer what do I need you for? 2k is chicken shit. Unless the idea is a throwaway, something I'm not passionate about, I'd just build it myself.
Suppose you have more seemingly good ideas then you could possibly build yourself.