I'd say the relationship between quality and price is more complex. A lady could charge €80 for massage and decide to charge €20 more. Will the quality of her service really rise by 25%? And how is this demonstrated/measured?
Secondly, my experience is that there is not always a straight link between price and quality. Price often probably reflects cost of accommodation/location (which, in fairness, can impact the quality of the experience to some extent) rather than the quality of the service.
Thirdly, punters will for the most part do what punters do in all walks of life and be influenced by price. And unless there is a real tangible difference between qualities of service price will wield a strong influence on decisions. It's unfair to hold punters to a different standard than a lady herself would show when shopping or buying any product or service. If you have a choice between two plumbers, one at €100 and the other at €150, are you really going to assume that the quality of experience with the latter is better?
Finally, there comes a point with any product or service where increased quality doesn't matter anymore, assuming the purchaser has limited funds. A house might have eight bedrooms and cost more than one with three, but if you don't need eight bedrooms the enhanced quality doesn't matter. That's not to even get into affordability and the fact that you might need money to do other things. Price will always influence most people. No reason why the business we're discussing should have different expectations. In fact if anything it is a perfect example of free market conditions - look at how the prices tend to converge around the same numbers. That's a silent acceptance that price does matter. Not clear why it should be an issue when punters confirm that.