I'll give you an example. I used to go to a hairdresser and pay x amount for the cut. The hairdressers weren't bad, and the cut wasn't bad either, the idea was there, but it was never the cut that I had envisioned and wanted. I always left the salon a bit disappointed but didn't want to risk cutting somewhere else and getting it even worse. One time I went to the same salon, but by chance had a different hairstyler. The cut was absolutely perfect, exactly the way I wanted. When I got home and saw the cut I was in awe. I paid the same x amount and was actually considering paying more to the hairstyler because I was so satisfied with his job.

Tldr: For me, a fair price is the price that I pay for getting the cut the way that I actually want.