The Margin Billing add-on adds cost and margin columns to the materials table on the job card.
This allows you to quickly set material and labour prices based on margin.
You can enable this by going to Settings > ServiceM8 Add-ons
From the job card, click Quotes & Invoicing tab
The Cost Price and Margin columns are now added.
To set prices based on Margin, simple type your desired margin into the Margin column. The sell price will update automatically.