(fact: you can pay more people $6 than $9).
...
The fact that we'd like everyone to live comfortably doesn't change that reality.
My issue with this is that yes, you can hire more people at $6 than at $9, but then if those people making $6 can't afford to meet their basic needs, that creates problems elsewhere and usually results in some form of government expenditure. So, by paying $6 instead of $9, you might "save money" in the short term, but there's no real savings in the long term: Someone - usually taxpayers (including business tax payers) - has to make up the shortfall; otherwise we have people living in poverty who can't meet their basic needs, which contributes to crime (which affects everyone), poor public health (which affects everyone), the disintegration of social capital (which affects everyone) and so forth.
(I'm simplifying here because we're assuming that there is only one source of income per household; many of the "working poor" actually can meet their basic needs, but only with multiple sources of income per household. This creates plenty of problems of its own - especially when it comes to raising a family - and if even one of those sources of income dries up - such as during a recession - then all of the other issues come into play as well.)
To me, I feel that it's better simply to pay the $9 up front to someone who is actually working for it and helping to generate a profit, rather than pay $6 to "save money" and then have to deal with the rest of the problems - only to get stuck with a tax bill for the extra money anyway. That's just my personal take on it, though.