Alternatively you could have accrued the salary deficit as convertible debt that would roll into the next funding round, at a discount -- which is a bit more anchored than estimating a 1% chance of exit at $600M valuation (if you were serious about wanting the job, which it sounds like you mostly weren't).
All these figures are subject to debate and would be more realistically modeled by probability distributions, but I was looking for a back-of-the-napkin quick estimate as a starting point for negotiation.
I also neglected to make explicit my use of the expected value of the exit in my calculations.
Seems like the key number here is the 1% chance of exit. If you really think the odds are that bad -- and I'm not saying you're wrong! -- then there isn't an offer they can make you that you'll take. They'd have to convince you that the odds are at least 5%, and probably higher, before there's a basis for a deal.
Averaged over all startups, of course, 1% is a reasonable estimate (might even be high). So another way to put this is, a savvy top developer just isn't going to join an average startup, period. They'll have to be persuaded that the opportunity is an extraordinary one. The bulk of startups will have to make do with less-experienced developers. This is why pretty much every startup now needs a technical co-founder.
> 1% chance of exit at 600M valuation after those 5 years
Ah, I see, I wouldn't have taken that into account since I'm not sure it quite works out that way. It seems you've intertwined probability with opportunity cost, is that correct?
EDIT: Thanks for the breakdown, by the way! I really appreciate the insight.
This is the right math if he's stuck there for 5 years, but his opportunity cost is lower if he can exit the role earlier if the company isn't trending towards the exit he wants.
That's true, I don't have a complete picture. I, probably falsely, assumed that he was being brought in as an employee in a team of at least a few people.
You wanted 7% equity to make up for 20k? That seems a little excessive...