No Stevie, NO! I don't share all the cost breakdowns with the client
That's internal information only!
If they know their project cost included $942 for travel time, or that I'm charging them for a can of marking paint - they would never pay someone to do the project!
I do however have a section of my proposal that says "this proposal is based on contractor supplying and installing the following quantities of materials, any additional materials will involve additional fees: 362 SF Holland Stone pavers, 152 SF Celtik Wal, 54 linear feet Celtik Wall caps, 24 tons of CR8, and 8 cu yds of screened top soil".
But on the proposal I do not break down edge restraint, fabric, spikes, adhesive, bedding sand, poly sand, marking paint, porta pot rental, fuel, etc.
Clients makes changes from time to time. And sometimes some people do not want to pay for the changes. Well, when changes are made - it usually entails the need for more materials.
Last summer we did a circular patio with a block wall holding up the patio. It was a perfect circle. The guy was working me on price during the negotiation period. So I calculated to the exact sq ft the materials needed. And I mean exact. So we did the job, perfect circle as on the design, and so forth. Client decides he wants to move the patio edge about 18-inches. This not only distorted our perfect circular patio and made it egg shaped - but it also required additional wall block and caps.
The client argued with me for 30 minutes (no exageration) because he did not want to pay for HIS changes. I said "look, the contract lists this quantity of material and we used every bit of it, we do not have one single block left over, the only way we will make this change is if you pay for the materials". He paid for the materials. But it got very heated in getting him to.
So no, you don't wanna share all your expenses with your customers. Toyota does not break down all the costs affiliated with building a car on the invoice.
But you should list quantities as I exampled above. So many reasons why you should do so, it would take me forever to go over all of them. I like 99% of my customers, but there are a few out there that will try to squeeze the most out of a contractor that they can and you need to be prepared for them.