A big deal with this may be due to upbringing and what part of the country/world you come from. While part of me dreams of being able to do this kind of work (I’m the exploration type), I can’t, since I can’t drive, limiting my searching ability. Regardless, my background keeps a nagging sense of impropriety of arbitrage in my mind. To my parents and my childhood role models, it’s not “real work,” since it neither creates anything new or abides by the “sweat of your brow” requirement my more religious acquaintances would demand.

TL;DR: I believe in “work smarter, not harder,” but most people I know/knew believe in the opposite.

I agree that there's nothing necessarily dishonourable about arbitrage, and I agree that based on his story, this man is doing honourable work.

However, I think that there is a potential problem in some arbitrage. Arbitrage depends on information asymmetry, and I think that labouring to perpetuate information asymmetry is unethical. (I would say that failing to eliminate the asymmetry when you could easily do so is a grey area.) So if you are an arbitrageur in an area where the market is trying to eliminate your advantage, you have a moral hazard.

This perspective was driven by utilitarian ethics, of course.