I have a hard time believing someone made $75K in one year on mturk with no month under 3K. I've had masters since 2013 or so and believe me, they are selling a dream. If someone makes that/made that, they certainly aren't sharing besides the generic "get the right qual, dude"
Well, no shit. If i had the qual for a batch that made me 75k/year, I'd be selling that sucker for over six figures