In a city where there are fewer regulations on the marketing of medical services, more doctors tend to promote their practices, and those who advertise specific treatments typically charge lower fees for those treatments compared to doctors who do not advertise. Consequently, if the city were to eliminate some of its existing regulations, such as the one prohibiting advertisements that do not include pricing information, the overall costs for medical services would be lower than if the city maintains its current regulations.

Which of the following, if true, would most seriously weaken the argument regarding overall medical service costs?