How would a "resident mechanic" lower the price of anything?

Wouldn't be trying to make a profit on the repair, would perform regular maintenance on all vehicles (so the break less), and would be able to diagnose/troubleshoot minor issues before they become serious problems (low tire pressure = blowout later).

The economics of living in a cheaper place is true, but you also have to deal with getting there and obtaining some sort of visas. Not everyone has that option. This would be something more for people who are trying to better their lives in the US.

In fire stations, there's a fire fighter who can cook good meals, you don't need a chef to make food.

True, but I don't like cooking. I think its fine to have someone dedicated to providing three delicious, nutritious meals every day. But this is clearly just my opinion.

You need to propose an economic plan first.

I was hoping to achieve some discourse with people here, and work out a plan together. But so far, people have only wanted to criticize the idea, or, be handed a pre-made full-proof idea. Then they'll "think about it".

You do raise some solid questions that need to be answered. Considering the lack of suggestions, I'll have to come up with some time to flesh it out myself :P