Azure SQL database vs. Azure VM running SQL server -- what's the difference? I've got two B4ms VMs running with Standard SSDs.

One is attached to a 100 DTU elastic pool SQL database.

The other has SQL Server running locally.

I'm running some insert-heavy SQL.

The locally hosted SQL server is running the SQL probably 7-8 times faster, but I'm paying another $300/m for the 100 DTU elastic pool database.

SQL is identical, both starting from "blank" databases.

If I were to get equivalent performance I'd probably be paying some thousand per month.

Am I doing something wrong here?