Your pricing and practices are extremely fair and considerate to your clients.
Slightly tangential, the doctor charge is (or was, or should be) a charge for the community. Wealthier patients pay (much) more, so that the Doctor can treat the whole community, and charge middle and lower income patients a different rate.
Maybe the Doctor providing medical care is seen as a social benefit, so there is not some anxiety or guilt about charging more.
There is a term - "price discrimination" or "differential pricing" for this situation.
I would feel bad too.
However, reflecting further on it, and reading about it; it seems that it is part of standard business practice in many industries. Of course, you can, and do, opt to provide higher value to your clients.