For starters, I wouldn't consider anything valued under a threat of ending up on streets to be "the real value". If you can be scared by the prospect of losing your job ruining your life, it's not valuation - it's coercion. You can't end up with market valuation if you are forced to take an unqualified job just to live, this will massively undervalue such jobs. You don't find out what's the value of having clean toilets - you only find out what's the lowest wage people willing to do this job will manage to live on.

I basically agree that it's coercion, but I think it's hard to draw a line where coercion ends and "free choice" begins.

Maybe we could get society to agree that everyone should get some basic set of inalienable rights that includes rights to housing, enough food to eat, etc. Enough so that losing a job didn't threaten your life or health. This is basically what social welfare systems already do. But I think that the quality of life afforded by taking social welfare instead of working must be kept lower than the quality of life afforded by taking any form of work, otherwise there's no incentive to do unpleasant jobs. If social welfare enables a completely comfortable life, I think one of two things would happen: either the price needed to get a toilet cleaned would shoot up to a level that would basically inhibit most ordinary businesses from forming, or it would become the norm for people to clean their own toilets at work. The latter wouldn't be so bad, I think.