You are definitely selling yourself short. This is one area where you absolutely must not trust your instincts; they will give you wildly wrong answers. A rule

You are definitely selling yourself short. This is one area where you absolutely must not trust your instincts; they will give you wildly wrong answers. A rule of thumb to start off with for calculating freelance/contract/consulting rates is to assume 1000 hours/year and figure how much you need to charge for what you want to be earning. By that rule of thumb you should be charging at least $120/hour - arguably more because this is your precious free time you're giving up, placing your health and happiness in danger, and you don't really need the freelance gig. If they balk at $120, they were never going to replace your day job and you're better off without them.