For $10K seed money for a typical YC funded company ($150k for 20%?) that amounts to 1.67% of equity. If you could convince people to sell 2% of their idea for

For $10K seed money for a typical YC funded company ($150k for 20%?) that amounts to 1.67% of equity. If you could convince people to sell 2% of their idea for 10k maybe it could work (!) How to validate ideas and teams and markets, though?