I finally got Birkenstocks just because they are apparently bullet proof and comfortable, but after something like 18 months of wearing them non-stop (almost every day), they have completely worn through and are not usable.
After that I had a pair of Walmart flip-flops that lasted only half the time under similar use but they were 1/10th the price.
Before that I had a pair of no-name not flip-flop (i.e., velcro strap) sandals that lasted nearly 6 years of fairly continual use.
There is no particular moral or conclusion here, they are just anecdotes. I just think you can't make any general rule about "it's better to buy quality than cheap" or vice-versa: it's all situation specific and depends on the quantitative costs and lifetimes.
There are many examples of "it's expensive to be poor". There also many examples of where it's not, and how people have what would have been considered a very high standard of living in the past on minimal output. Many not poor people are also definitely not doing the boot anecdote thing posits: they aren't buying one set of boots and wearing them their entire lifetime. They aren't buying one set of hardwood furniture they use from their 20s until they die and they aren't buying a quality vehicle and running it for 20 years on synthetic oil.