[scaryclam]

I hope they're paying you a rate for your work alongside the stake. Working for free is a mugs game. The stake is worth nothing at this point, so no, it's not payment in itself.

That aside, holding down a full time job and committing to other work as well can be tough. Do as much as you feel you can, but say no when you want a break. Burn out is no fun.

That aside, how much you work depends on you and what you're willing to do.

But again, stakes are not payment, so don't work for free.