Let's do some arithmetic for you. At 125k/8%, you're giving up $50k salary for 8% equity. At 100k/15%, you're giving up $75k salary for 15% equity. But it is

Let's do some arithmetic for you. At 125k/8%, you're giving up $50k salary for 8% equity. At 100k/15%, you're giving up $75k salary for 15% equity. But it isn't 15%. If it's a typical 4 year vesting, it's only 3.75% per year. So you're giving up $75k salary for 3.75% equity in the company. That implies a current valuation of $75k/0.0375 = $2M. But you are a minority shareholder. You could do a great job, deliver a great MVP, and then be fired after 11 months with nothing (if it's a typical 1 year cliff). The founder could give a sweetheart deal to friend investors, diluting your equity. Your shares are common, not the preferred an investor would get. So the CURRENT VALUATION of the company needs to be a lot more than $2M, for this to be a sensible risk for you to take. There are two disasters that can happen to you. The startup could fail and your equity is worth nothing. The startup could be a smash hit success, and you get cheated due to your status as minority shareholder. So you'd be better off keeping the job that pays $75k more CASH, and investing the difference. I doubt his idea is that super-brilliant. The fact that he went this far without a technical co-founder shows that he doesn't really value that aspect of the business. You'd be better off saving/investing the extra $75k salary, and then self-angel-investing in your own startup later, where you could be a TRUE co-founder. Also, as the above people said, a co-founder does not normally draw a salary at the beginning. They are expected to work for equity only, which seems like an idiot move for someone who could get $100k+ CASH as an employee. To give up that much salary, you'd need to be getting half of the equity or even be a controlling shareholder. So, keep the job that pays $175k, save up the difference, and invest in your own startup someday where you could be a TRUE co-founder.