Need help deciding comp for founding engineer role

I recently got an offer for a founding engineer role at a very early stage startup. The product is not out yet and the role is meant to be building the initial product to be sold to customers who have showed interest in it. The startup is in the payment ops space. The comp offered is 15lpa and equity of 10lac or 0.5% whichever is higher. I have 3.5yrs of experience and left my job in October last year. I had an exponential growth in my package while moving companies and made 45lpa + ESOPS in my last job, starting with 4.5lpa as a fresher. I know that I might not be able to get the same comp now given the scenarios in the software and tech industry. I wanted to know how to best analyse a comp package for a founding engineer role, particularly at this point in time?