Enough to pay for a basic standard of living if they're working full time. If not, why would anyone work that job?
This point about "skilled labor vs. unskilled labor" is meaningless. If you work 40 hours a week, regardless of what you are doing, be it standing as still as you can for some rich guy who enjoys watching people stand completely still, counting the minutes it takes for paint to dry, watching CNN, asking people "what time do you have", ANYTHING, if you work 40 hours a week, you should be compensated enough to support yourself if someone is willing to pay you for it. The work you do is not relevant to this conversation. This is America, people shouldn't have to work more than what is outlined as an average working week, if they do, the average working week should be changed to account for it, and until it is, the 40 hour a week model is what we will use. Wanna bitch about it, lobby congress to change it, otherwise, simply, shut the fuck up about it and pay your workers what you fucking owe them.