Yes. In a free market very transaction is a short form negotiation. The shop says what they want for the job as a take it or leave it proposition. The buyer is free to decide which, or may make a counter-offer such as "$7.50 to adjust a headset?" Would you do it for $5?" By leaving a repair, you're tacitly accepting the price. You don't have to like it, but you are accepting it.

Meanwhile we've had lots of comments about how dealers set prices. The reality is that consumers as a class play a major role. The concept of "what the market will bear" is very material here. Regardless of what you're charging, if the shop is booked up, and you're running at capacity it's probably a bit low. OTOH, if the shop isn't at capacity, and people are routinely griping about prices then you're high.

There'a also "capacity pricing" which may depend on seasons. This is why many shops will build wheels or do overhauls at much lower prices in the off season. The electric company does this, charging more in the summer than winter, and some also having day/night rates.