I don't care how much the average salary of Czech is (I would have thought way lower though, I should ask Lemon to check), we don't know where he lives and don't care, I said "basically you want a salary at NL5" because he asked for an hourly rate that would make him earn about 1200 by month if he grinded as much hours as a job would roughly make.
You can make a living at NL2 if you live in China and all sure but living in China doesn't change your winrate at the tables, I highly doubt someone could make 19bb/100 on 4table zoom without having better to move up and play at least midstakes because that's clearly the type of winrate real pros achieve when they try a microstakes challenge for fun (or they might not even reach that in that case but whatever).
I've never heard of people making so much at NL10, only at NL25-50, but I might have missed something. I wouldn't advice trying NL10 for that though lol. NL16 or even NL25 are less reggish, less nittish and should be playable for the same volume with pretty much the same amount of skill although it could depend a little on your personal playstyle.
A little note about average salary : it's a really bad measure of the average citizen, in fact most of the time no less than 2/3 of the people of a given country live with less than its "average salary" so much the richest blur the average tendancy with their unbound wages. The medium (or median) salary is therefore a better indicator.