What are the costs associated with a SaaS-linked Office add-in?

[CBullen1]

Hi,

I'm hoping to soon submit an addin for Excel, which I'd like to provide in a 'basic' and 'pro' feature set, where the 'pro' feature set is enabled by purchasing a subscription. Is it still correct that I have to do that by:

- creating an Azure tenant

- creating a SaaS application in Azure, using Microsoft's licensing

- link the addin submission to the SaaS application in Partner Center?

If so, what is the charging model for that? I guess that every time my addin starts, it has to check with the saas end-point to see if the user has a valid subscription. Is there any cost associated with that checking - i.e. does it count towards the number of 'hits' / logins my Azure subscription allows? 

Ideally, I'd be charged a small % of the subscription fee, with no per-usage charging of any form...

[#2]

@CBullen1 

It may also depends on SaaS and type of terms

[#3]

Thanks @Kidd_Ip. It seems there's a lot of documentation about the technical aspects of creating an OfficeJs solution, but very little about setting up the infrastructure and processes around it. It would be very useful to have a "Step-by-Step guide to set up a subscription-based addin", starting from an individual developer with a personal MS login and ending up with a published subscription-based app, including the organisational and financial aspects, not just purely technical.