You'll have to negotiate with very little leverage unless you consider more than one brand, or travel to other cities, or do some comparative shopping over the internet. The technician will take care of that for you . Don't buy it. Tone quality especially is too subjective, too undefined, too inexact a science to make any promises to please. Having taught and having observed many different piano teachers and their students for so many years, I have to say that I no longer know how to answer this question.
Music is such a big field.
Every teacher is different. Every student is different. It's pretty much a matter of finding a match that works. I guess you should just try a teacher out. Piano lessons are really adventures in psychology.