It obviously should be a term both parties should be happy with regardless of what that may look like. If neither party are happy, it won't matter. Do you believe in the company and founders?

Having said that, more details would actually help people here give better feedback. How early is early, aka employee number 1, 10, 20? Has the company raise funding? Profitable? How long has the company been around? What position. These factors and others, can influence a lot.

Generally speaking, depending on what stage of funding and how early a startup employee you are, it can vary between 0.5 pt to 5 pts. Of course there are ranges outside of this as well. Salary can vary a lot too. I've seen engineers do as low as $24k/yr to at least $50k/yr.