A risk reward game

Startup valuation is a dark art. Even if you see hundreds or thousands of startups a year it's still hard.

As an investor, you are playing a trade-off between risk and reward.

All other things being equal, what multiple could this business reach if it achieves its maximum outcome? Given the founders, the plan, the competition and the trajectory, how likely is it to move fast in that direction?

Put those things together and you may not have a specific valuation but you will have a way to compare different startups of different valuations.