I pull over 10k gross a month easily submitting galleries with all my sponsors combined. I think I would be happy with 20k a month cause that way I can travel as much as I want plus shop all the time and not have to think about money as much... I'm not there yet, but hoping to be there soon.
Before porn I was working full time in an office and only made 30k a year (around $14 and some odd cents an hr) so making 6 figures is a big improvement for me

BTW, I do think 30k is the average salary in the U.S today and I was able to live on 30k fine (by myself). Of course I couldn't afford really nice clothes or fancy things back then, but I was able to live just fine.