Cost of Azure services does not necessarily depend on the level of their utilization. For pricing information, refer to https://azure.microsoft.com/en-us/pricing/details/azure-sql-database/single/
Switch to serverless model whenever applicable if you want to minimize cost for services you don't use on regular basis
For more info, refer to https://learn.microsoft.com/en-us/azure/cost-management-billing/costs/tutorial-acm-opt-recommendations
https://learn.microsoft.com/en-us/azure/cost-management-billing/understand/plan-manage-costs
If the above response helps answer your question, remember to "Accept Answer" so that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.
hth
Marcin