That's still quite good either way, but OP should understand that even in most expensive US cities a journeyman plumber is typically pulling at most like $150k-$200k without doing significant overtime. And you won't get there until 5++ years on the job.
So think more like $100/hr of actual compensation on the higher end.
Not a bad gig at all. But that $800 number comes with a lot of caveats.
My side gig pays around that, but there aren't many hours involved it in, and there isn't a good opportunity to find more hours, so it isn't all that much money at the end of the year. It is a tidy job for the effort required, but you wouldn't want to have to live off its income.