I mentioned that in another comment, there are certainly a lot of cases like your example where it makes no or not much sense to apply a minimum wage. I want the minimum wage to target specifically normal (full time) employment. An employer should not be able to pocket most of the money for say selling relatively expensive cloths but pay shitty wages to its sewers. You might argue that employees are free to negotiate wages and free to not accept bad conditions, but that easily fails if, for example, there is a surplus of possible employees. Sure, it is an important mechanism to reduce costs for consumers, but that should in my mind not come at the expenses of the employees.

I think that devolves into "I can hire Matt, the neighbor kid and pay him $5/hr, but I can't hire Matt Inc, the landscape company, because they aren't allowed to pay Matt [the neighbor kid] $5/hr"

All of which perpetuates the cash/grey economy (and the off-shoring of garment-making jobs in your example).

The thing about UBI is that it allows employees to turn down bad economic deals without starving. Sure, you can't live in a 2000 ft^2 house, drive a new car, eat and party out all the time, but you probably don't have to take a job with ridiculously bad conditions just so you can buy a can of beans or Ramen.

But that seems not unreasonable on its own. Tipping a friend $20 because he helped carrying boxes when you moved as compared to hiring a professional mover for $20 seems like a valid difference to me. But you a right that this could maybe be turned into a good argument for an universal basic income because you may be able to sidestep some otherwise relatively difficult to solve gray area issues, but I am not sure, I haven't thought that through.

You think $40 is excessive for a morning's work? I really don't know what to say to that that won't attract the wrath of dang. Perhaps he can suggest some polite words...

I didn't say I thought $10/hr was "excessive". What I said was that that was more than I was willing to pay to have that particular problem solved.

There are all sorts of things that people will pay a handful of dollars for, but that they won't/can't pay $10/hr for. Mine was just a concrete example of a low skill required task that I don't enjoy and that someone whose basic needs were already covered might be interested in doing, much like I did when I was a kid/teen and wanted to earn some extra money.