There's no universal answer for this. The amount one can make will vary wildly due to region, style of show, marketing ability, and discipline.
I am currently on the low end of things, as I have a good day job that pays me enough. I won't leave my house for less than $400, and that's generally only if I'm giving a deal. For bigger events or longer engagements (weekend fairs, for example) I'm closer to $1,000. These are not exact numbers.
In Fresno, though, I would have trouble pulling in more than $200-$400 for the same gigs, because that are is saturated with "performers" who will work for free.
It also depends on whether you're focused on getting a set fee for your performances, or handling door splits/ticket sales.
For set fees, I know a guy in Baltimore that won't do a show for less than $1,000. Another guy in the DC area is $2k-$7K per gig. A guy in Florida is $3K-$10K per show. A friend up in CT makes at least $25,000 a year doing nothing but performance (that's a low end estimate, he's usually significantly higher).
A lot of that depends on how good your show is, and also how good you are at marketing it. Marketing gets you the first gig, the quality of the show (and how much they like you as a person) determines how many repeat clients you have. The more repeat clients you have, the less you have to hustle to make your living.
A guy I know in CO made 125K from a door split residency he has, which is pretty darn good. But he's spent, I think, about 7 years getting to that point. When he started it was much, much less than that.