Unfortunately, there are consumers, who only see price. So, the more value we put into the job the better. In order to avoid customers questioning labor and/or your overall price, you need to do a few things: Bring value to your services and repairs, know your key profile customers (the people that trust you and don't question you) and instead of selling parts and labor, sell you and your shop.
Let me explain. Outback sell steak...just a steak. So the price has to be fairly low. Their brand caters to a particular segment of the population, or to consumers that are looking for a good meal at a reasonable price. Now, Morton's Steak House or a Ruth Chris Steak House, does not just sell steak. They sell customer service, fine dining, atmosphere and they sell the "experience." Their steaks are 4 to 6 times higher in price than at Outback. Is the steak at Morton's 6 times better than at Outback? Who knows. But the point is they can charge those prices because they have done a great job at removing price from the equation and replaced it with a lot of value.
The best shops and the most profitable understand this concept.
Don't sell just a water pump, if you do, you will be in trouble. You are not a Deli selling commodities like milk or eggs. If you were I would say price IS a concern. Bring value by telling the customer what they get, all the little extras you do, the warranty, the follow up inspection. Anything that positions yourself different from the Shop down the block. And find the Right Customers.
Lastly, be careful of comparing your prices and matching your pricing by what other shops charge or base your prices from and online source. You should not "cookie cut" your services and repairs.