If I might suggest a simpler question? "How do I value this idea maximize my odds of getting genuinely rich from this venture?" The question isn't "how much i

If I might suggest a simpler question? "How do I value this idea maximize my odds of getting genuinely rich from this venture?" The question isn't "how much is this worth?" at all. It's "how do I price this to maximize the odds of success and the dollar worth of my share." If you do very well and sell for $10m, the practical difference between 33% and 50% in terms of your quality of life is quite small. On the other hand, a feeling of uneven split between founders, particularly as the start up moves further and further from the basic concept you started with, is a potential contributor to a "50% of nothing is nothing" situation. Once the game starts, it doesn't matter who put what on the table: if you're not actively getting screwed get your head down and focus on making what you "own" worth something, rather than worrying about how the loot is divided.