You're assuming that when you're wealthy you can go buy things when they're in bulk. Because it's the question of startup capital, really: if you can spend your money up front in the right places wisely, then you'll save money in the long term. But if you're constantly struggling just to kind of patch it up and make ends meet, you're taking whatever the most convenient option is, which is inherently going to be more expensive.

A wealthy person can just afford to take [a broken car] to a decent mechanic and make a good repair. A poor person is going to jury-rig that thing with literal baling wire and duct tape, and it's going to do more harm to the car in the long term