is it evil to try to charge as much as you can? I would argue no. Certainly, in the case where my product is limited, such as when I'm selling my time, I put effort into that. Is it evil to spend time trying to charge more for the same product rather than spending that time making a product that is worth more? maybe. It's certainly not admirable.
I explained in a previous comment that I think not differentiating, and instead competing on price and value can be a good strategy, especially when industry margins are high.
I work in computer repair as a sole proprietorship, and if I charge too much I won't get repeat business. But you can't always judge if someone will refer more customers to you or give you repeat business.
when I say 'charge as much as I can' I mean 'set my hourly rate as high as possible' where the hourly rate is set before the work is done (and usually before we meet)
I explained in a previous comment that I think not differentiating, and instead competing on price and value can be a good strategy, especially when industry margins are high.