What's actually going on
This is a really common quoting-software snag, and it's a quick fix — no need to master the whole quoting tool to sort it. Most quoting screens are built for costing first and showing second. You add a material, the screen wants a quantity and a price, and if you're marking it up, you type the margin onto that line. Do that on every line and the same 20% gets typed in over and over.
The document your client sees is generated from the same list. So by default, they see every material, every quantity, and — if you're not careful — the maths that got you to your price.
That's not a flaw you have to live with. It's just what happens when one list is asked to do two jobs: your internal costing, and your client's quote. Those are different documents with different audiences, and treating them as one is what's slowing you down and oversharing your margin.
The smallest fix you can do today
Split the two jobs.
Keep one working sheet — your material list, quantities, supplier prices, and your markup — as detailed as you like. This is your file for ordering and for timing the job. Nobody but you sees it.
For the document the client sees, you don't need one line per material. Most quoting tools, including MYOB, let you add a line with just a description and an amount, without picking it from an item list — MYOB's own guide says: "If you're quoting for a service, enter a Description and complete the Category, Amount and Tax code / GST code details" (MYOB: Working with quotes). Use two of those: "Materials" and "Labour," each with just its total. If you're on MYOB AccountRight desktop, you can also add headings and subtotals to group things further — check your version for what's available, since the browser and desktop versions differ.
Your working sheet stays the source of truth. The quote becomes a two-line summary pulled from it, not a rebuild of it.
When it's worth keeping, cleaning, connecting, or converting
Keep what you have if this is a once-a-week problem. Manually copying two totals across takes a minute and isn't worth touching.
Clean it if you're quoting daily and the margin-typing is genuinely eating time, or if a client has ever seen a price they shouldn't have. Cleaning means fixing the habit and the sheet layout — no new software, just separating the two documents properly and maybe adding a formula that pulls your two totals into the quote screen for you to paste.
Connect it if your costing sheet and your quoting tool could talk to each other — for example, a spreadsheet formula that outputs the exact two numbers you need, ready to paste, so there's no manual addition at all.
Convert is rarely justified for this specific problem. Quoting behaviour like this exists in most tools; changing software to fix a workflow habit is usually the expensive way to solve a cheap problem.
What "done" looks like
Done means you can build a quote without opening a calculator or re-typing a percentage, and your client only ever sees two numbers plus a total. You'd know it's fixed if quoting a twenty-item job takes about the same time as quoting a two-item job — because the client-facing part no longer scales with how many materials are on the sheet. If it still takes longer for bigger jobs, the split hasn't actually happened yet.