Maybe this comes from what the post says about "knowing what to buy", but I bought boots made by a 2nd generation shoemaker constructed out of leather carefully prepared here in Chicago. They're recraftable so I figured after the bottoms wore out I could fix them. But here I am a year later and the inside sole is coming up and squeaks with every step. I'm going to have to take it in to get it repaired, for probably $15-$20. From a consumer waste and natural resources perspective, I'm still happy with my purchase, but I'm pretty convinced that shopping every year or two at Walmart would leave the average person ahead, cost-wise.
More generally, I wonder to what extent the Vimes theory is true. Richer people buy higher quality items and generally have a more luxurious life, but I'm not sure that it's cheaper overall. Or at least, there's a point where it's obviously the case (c.f. the T ticket vs Charlie card point in the post), but I think it happens pretty early on in wealth.
Case in point, I bought a nice 2 year old Chevy from a dealer with low miles for $12,000 a few years ago and haven't had a problem with it. I can imagine that paying itself off quite easily vs. making do with a $3,000 beater that keeps falling apart and needing service. But from a purely cost perspective (not luxury), I don't think beyond maybe $15k or so, more money in a car will save you in the long run.
So, I still kind of get Vimes' theory, but I only think it applies from, say, poverty to lower middle class level. Beyond that, I think upper class people spend more money on stuff, and get a sweet life because of it, but not as a cost saving measure.