And for the kinds of goods I buy, in most cases it doesn't hold up. Cheap shoes might be only 25% of the price of good shoes, but in my experience last 50% as long, costing less overall. Compound that with other chances of loss (getting dusty in the back of a cupboard and eventually being thrown out in a declutter), and cheap works out far cheaper
And the point Samuel Vimes is making goes far beyond a simple "If you buy cheap, you buy twice." It extends that basic knowledge by realizing that some people have no other option than to buy cheap, forcing them to spend resources over and over and over again and still get a worse result in the end, and how this is a fundamental and systemic social unfairness.