Azure subscriptions in Work 365 will have a 17.7406 markup % by default 
This is because it's a calculated mark up % for the standard 15% markup for Direct CSP partners with Microsoft.
Work 365 imports costs from the Partner Center APIs to through the Daily Rated Usage file. This file includes the detailed lines with the cost associated with each line for Azure consumption. To achieve a 15% margin the reverse calculation for MSRP on Azure cost is 100 x 85%= 15, then 15 divided by 85= 17.647058%.
A 17.64% markup on the costs is equivalent to a 15% margin on the Selling price.  
Then when the consumption is synced from Microsoft Partner Center, the markup is automatically applied to the Azure consumption. The Work 365 invoices then calculate the Azure totals including the markup %.