@elliottchandler the Azure Pricing Calculator has now been updated to provide slightly more accurate pricing information (Pricing calculator | Microsoft Azure). This now will provide a price/user/month, however doesn't include any M365 costing, so there are still some elements that you need to add.
We've also got the solution configurator which can do something similar, this can be found on our partner page for AVD. I do find that it's often best to build estimates from the base resources being used, please reach out to me if your partners need help pricing up their solutions.
