This is always a challenge with many businesses. In some businesses, the service provider explains what they do and then offers options to reduce the price by modifying the service. However, some are rigidly stuck to doing it one way and consider it an insult to do "less".
As a consumer myself, it helps to know how a company prices their work. For example, if they say they need $50/hr to cover their work you have a baseline to judge value especially when labor time is a key variable. Customers may be accustomed to expecting discounts (there are so many coupons out there).
Interesting some detailers are cheap when buying products but seem insulted when one of their customers challenges their prices.