Purchasing better quality costlier things is cheaper in the long run


BS example imo, who really buys boot worth >month salary. Lol. No matter what the durability is
It's not about this particular example.
It's about thinking when buying the cheaper or cheapest item whether it serves one's purpose and expectation in terms of quality & durability.
If not then one can go for less cheaper option which ultimately might proven cheapest due to better quality and/or durability.

Nowadays quality has gone down drastically

I got the idea, even I follow the same, but the example used is really bad, imo. There are many better and practical examples especially when someone is writing a book lol Nobody buys or should buy boots worth more than one month of their salary.
Yes the example could have been better for sure.

You are assuming everyone is a connoiseur in all things they buy. It is super "safe" (and thus, smart) in buying the most affordable, popular and market price item. Thats my theory of socio-economic brevity.
I am not saying that one should always shell out extra bucks.
But one should keep price, quality, usage and their own expectation of the time till the product should be usable in mind when making the purchase decision.
Sometimes going for the cheaper item may become costly in the long run if one thinks from the criteria mentioned previously.

This theory assumes the slightly costly boots would actually be worth their price. This is often not the case in the real world since certain substandard products are often marketed as superior products.
Not to mention demand and supply also plays a role
Yes that's correct.
It's not always the case.
However sometimes we go for the cheaper/cheapest option to regret it later.
Hence one should very carefully purchase the things especially if they are too costly to regret later.