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.
It does create something new, it creates value. I'm amazed at the 'arbitrage is bad' comments, I can't remember seeing it anywhere before. Someone who finds a buyer for a thing that couldn't be sold before (i.e., was worthless) creates value by enabling the transaction.
It creates a new opportunity for the seller - those individual books were previously not available online. they were just sitting in a bookshop.
Finding these books, then placing them online, and handling the shipping to the buyer is certainly adding value.
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.
This example, at least, does not depend on asymmetry of information. It depends on the willingness of the parties to invest extra labor.
The business model of the thrift store requires treating the books as commodities ("all hardcovers $2/ea", etc.), as they don't have the volume to invest time in research. The business model of the used book seller requires knowledge, amortizing the cost of researching each book over a global (or at least national) customer base.
Adam Smith would find this a wonderful example of division of labor.
TL;DR: I believe in “work smarter, not harder,” but most people I know/knew believe in the opposite.