Actually, I bet it's very profitable.First of all, it's all cash which really lowers the tax liability.
Secondly, I've seen raw cost numbers like $100 per pair. If you spend a couple of dollars on truck decals and brochures with phony reviews, maybe you're looking at $110 per pair, tops.
A few bucks for gas and you might sell two pairs in a day, maybe $600 per pair. That's a gross of over $300K per year for a couple of fast-talking high school drop-outs.
Not too shabby.