Hi @Kamil
As you mentioned, 90% of the cost is going towards database usage.
To save the cost, what you could do instead is switch to a lower-cost tier or switch to serverless tier with auto-pause enabled. With auto-pause enabled the server will pause if there is no activity during the time period you set (minimum of 1 hour).
You can change the tier in the portal via Settings -- Compute + storage.
Serverless compute tier for Azure SQL Database
Additionally, to save the cost, there are several options that could be helpful.
Please check in below link How to stop Azure SQL Database - Microsoft Q&A
Let us know if you have any additional questions.
Thank you!