Years ago I assumed the clients spending the most money would be the most demanding, and braced for every interaction accordingly.
The opposite turned out to be true more often than not. The clients spending the most were frequently the easiest to work with, calm, decisive, low-drama, because they'd already done the deciding before they walked in.
It was the smaller, more uncertain purchases that came with the most back-and-forth, the most second-guessing, the most hand-holding.
I stopped correlating price with difficulty a long time ago, and it changed how I prepared for every conversation.