Charging of a "pay-as-you-go" SQL Server Instance

Hi all

I am occasionally providing support for a customer who has a quite large SQL Server database. In order to keep my costs low, I currently think of using a SQL Server instance in Azure which I can fire up, only when I have to work on the customer dataset. I think I must then only pay for the amount of storage used for keeping the customer data persistent over time (and of course the SQL instance while it is up and running).

My questions:

- Is my understanding correct that I only pay for the SQL Server instance when it is started up ("pay as you go")

- What storage type can be used in Azure for holding the SQL data persistent so a newly started SQL Server instance can make use of this

- Anything important I missed in this scenario?

Thanks a lot!