Ultimately, you can choose to compare apples to oranges and say that the oranges are cheaper, but oranges will make a really bad apple pie.
What I'm trying to say here is that it's all well and good to talk about how mechanics' wages will go down to $9/hr, but there have been tons of studies that prove what has been alluded to here, that the quality of employee tends to go down. Within a certain wage range, the quality difference might not be significant, but beyond some point (where that is isn't clear) the real costs go up.
For example, if you pay $10 instead of $15, but the work takes twice as long to do by a $10 employee than a $15 employee, you're no longer saving money. Instead, your mx labor costs just went up by 30%. Of course, if you're talking about work that isn't done correctly at $10, things get worse in dozens of ways.
Contrary to what some on this board might believe, I'm not a proponent of indiscriminate wage reductions. 😉