This is what the disagreement is over, though: empirically, do most people taking this route save money, or do they end up spending more money in hopes of long-term savings that do not materialize? It depends strongly on the shoe, wearer, and various failure modes (and how repairable / expensive to repair each of those failure modes is). In my own case, I've generally found that the expensive shoes fail to save money, because even though they're more repairable, the cost of repairs eats up any savings, vs. just treating shoes as a disposable good (might be different if I lived somewhere with lower labor costs; around here even a simple resoling costs $50, and anything more involved starts at $100+). That might still be worth it if you prefer the nice shoes, don't like unnecessarily sending things to landfills, or other reasons, but for me, from a strictly cost standpoint I've found it hard to come out ahead.
It took me a second to think through the premise that $600 dollar shoes might make economic sense. My guess is that people who wear $600 shoes don't walk to work, or really walk much of anywhere, at least not in their $600 shoes. So, they probably do last longer and fulfill the social signalling or whatever other purpose said shoes fulfill. I don't think anyone wears's shabby old 9 1/2 year old shoes that originally cost $600. I suspect people usually wear $600 shoes so that others can tell that they are not price-sensitive regarding footwear.
I doubt it. People who want flashy shoes that people will notice spend money on more exotic brands, not Alden or Allen Edmonds.
Shell cordovan is a bit unique amongst shoe leathers. It is valued by the people who wear it primarily because of the way it looks. Shell doesn't develop creases when you wear it, it develops "rolls". It also (at least in colors other than black, like Horween's famous Color 8), develops a patina that leather made from cow hide doesn't. It looks much better with age.
I just sold my late stepfather's 40 year old shell cordovan shoes for $100. They have seen lots of wear over the years, but are in great shape, and look amazing because of the afore-mentioned patina. That is why people pay that much for shell cordovan.
Obviously they don't walk in damaging environments, but you should be able to repair the sole if it gets used.
Another thing to consider aside from price and looks is that the design (how it is supposed to react on your walk) is fundamentally different from "cheap" snickers. For instance it's way more rigid and doesn't twist. For some it helps their walking, for others it's an hinderance.
This is what the disagreement is over, though: empirically, do most people taking this route save money, or do they end up spending more money in hopes of long-term savings that do not materialize? It depends strongly on the shoe, wearer, and various failure modes (and how repairable / expensive to repair each of those failure modes is). In my own case, I've generally found that the expensive shoes fail to save money, because even though they're more repairable, the cost of repairs eats up any savings, vs. just treating shoes as a disposable good (might be different if I lived somewhere with lower labor costs; around here even a simple resoling costs $50, and anything more involved starts at $100+). That might still be worth it if you prefer the nice shoes, don't like unnecessarily sending things to landfills, or other reasons, but for me, from a strictly cost standpoint I've found it hard to come out ahead.