I have a friend who bought a pair of 90K EUR speakers. A very bright guy in his field. Wasn't too happy with the sound, asked me. Turned out he was using BT from his iPhone to stream. That was 3-4 years ago, not even a good BT. If I had been a dealer, I could have approached the issue by saying "let me solve that for you by deploying my expertise, install fancy cables, fix the streaming (without necessarily mentioning it) and maybe add a totaldac to the mix.
One of my acquaintances (not a friend, those guys don't have friends) wanted a home theater and asked his reseller for "the best", gave him a global budget and ignored the details. Another one, also quite bright in her field, asked me to connect some equipment. There was exactly one output, one cable in the box, and one free input matching the cable in her system...