With all due respect we make our dinning decisions on a different level than we pick our service providers. Even between services we have a sliding scale, i.e. we might look for a good doctor, but we when we look for a plumber we qualify it with the word “cheap”, as in we are looking for a “good cheap” plumber.
It all comes down to value and trust, the customer wants to trust to the contractor and get a good and fair value for their money, but if they can’t trust the contractor, they don’t believe the value. Things like showing up on time, doing what you said you were going to do, keeping your schedule, owning up to your own mistakes, and having a good attitude , create trust. Things like being late, having a poor attitude, changing your price, gouging on change order and schedule over runs erode trust. If they don’t trust you, it does not matter how good a deal they are getting, they will think you are being dishonest.
I do not subscribe to the idea that transparent book keeping, and markups build trust. In fact transparent billing does more to erode trust than anything else. Some customers can count wire nuts and watch the clock and somehow come to the conclusion the three 27? wire nuts and ten minutes you took to put them on is a rip off, while others will call Home Depot to check your device prices, just to make sure that $1.30 a device you charged is not to much.
Never break down your price to nuts and bolts, it only fuels the fire of distrust. Instead create a clear scope of work that defines the work and schedule with a price that you can do the work for and make a little money. The scope of work should include the number of panels, fixtures, and devices included in your price. Sometimes if I am working on building trust, I will also include a unit price for adding lights, or receptacles before the sheetrock goes up (or even how much to add one as a wall drop). If they want a break down, tell them all the material is included for your scope and point out the scope clearly defines the quantities of big ticket items.
Keep in mind takes-offs and unit pricing is proprietary information and will be used against you every chance the customer gets, even to shop your number with your competitors.