What % salary increase would you want to move jobs?

Currently in a job which is good in the tech sector but ready for a new challenge when the right role comes around. Director level in marketing, £135k base, 25% bonus, similar amount in stock awards each year.

Just had an offer for a role that increases base salary by 15%. After tax - it doesn’t look like a massive jump. And it’s switching to a start up - so no bonuses, only stock which you hope comes good at IPO or selling off before (typical four year vest).

Unsure whether to leave or not. Obviously there’s more to a role than just the money, but if it was pretty equal in terms of culture, other benefits, career progression (etc) between your current company and a new company, what % uplift would make you leave?