Is there such a thing as a payment placebo?

A quick question, to which I’m sure there is probably an easy answer:

I’ve heard it said many times in recent years that physiotherapists in private practice should be confident enough to charge what they think they are worth, and that people only truly value something if they have to pay for it.

If which case, isn’t this just another form of placebo where people gain additional benefit because they’ve paid more?

And isn’t that at odds with the idea of evidence-informed practice?