When I think of the value of good shoes, I’m reminded of a rainy night I spent at a bar with a friend. He must have placed his foot on the barstool awkwardly, because when we got up, the front part of his sole ripped off. He had to run through a downpour to catch the bus with his sole flopping between the wet concrete and his shoe upper.
When buying shoes, it's crucial to examine how the soles have been attached. Broadly speaking there are three methods.
Traditional English shoes tend to be Goodyear welted, where the sole has been sewn onto a strip of material attached to the uppers called the welt. It's a heavier construction, but has more water resistance. More importantly, it allows the shoes to be easily resoled by removing the stitching and attaching a new bottom.
Similar is Blake stitching, where the soles are directly sewn onto the uppers. This allows for a slimmer profile, and like Goodyear welted models, can be easily resoled. Cheap shoes, on the other hand, have their soles glued on. These aren’t as easily resoled, and come with the risk of detachment (and the consequent embarrassment). Of course, there are exceptions. Suede bucks traditionally have cemented soles, and you’d hardly want Blake stitched slippers; but, generally speaking, a sewn-on sole is a sign of quality.
You also want the soles attached to some full-grain shoe leather worth caring about. Try bending the shoes where the foot flexes and see if the crease lines are small. If they are, the shoes may age well.
Why buy quality shoes? Partly for longevity. The higher cost of a nicer shoe is spread out over more years of wear. Cheap shoes, unfortunately, look bad after six months and may not live past twelve. But even so, you generally won't save money by buying more expensive shoes. To me the more compelling reason is that the lifespan of a quality shoe gives you time to develop a relationship with and appreciation for it. I’m reminded of a cardinal style rule – nothing looks good when it’s too new or too perfect. Character must be beaten into things. High-quality shoes eventually acquire that beautiful worn-in look that only good materials and years of wear can impart. They become friends that won't let you down, even in the pouring rain.