Any good auto repair technician realizes, but most customers would be surprised to know, there is no such thing as a "brake job" nor a "tune up." Decades of "commodity" marketing of auto service have lulled people into a false belief. The practice is called menu pricing. Trying to select service, like a commodity, simply by comparing price on a menu. In reality the practice may insure, not only unpleasant surprises with regard to price, but that they will be taken advantage of.
First, nothing identifies a person without a knowledge of vehicles [sucker?] faster. To a shyster, "How much is . . ." is an open invitation. Secondly, quality shops will not participate in the practice. They will simply try to explain why quoting prices is impossible. To a person seeking a quick answer, the bigger the charlatan the better they may sound. Unfortunately, the most honest person sounds the least plausible.
Any choice based on false information will inevitable be wrong.
In reality, a shop’s refusal to quote prices, without seeing the vehicle is a very positive indicator of their intentions
A far better practice is to check the reputation of the shop, with whom you wish to deal. Allow the shop to diagnose the actual problem and then supply a guaranteed price. Without first checking the vehicle, to know the extent of the problem, any price quoted is misleading at best and an outright lie at worst.
When dealing with an honest person, the price will reflect what is honestly wrong with the vehicle. With a charlatan, the price will normally be the most they feel they can extract.