I'd definitely accept toilet jobs for $5,000/hour, then subcontract out to a plumber for their going rate, and pocket the difference. IMO a bad example.
I probably would walk away from that, but my point is that if you are a contractor, then the requirement is simply that the work be done, not that you do it personally. If they're willing to pay absurd money for something you don't want to do but other people will do, subcontract.