Document DB is too expensive

Hi, my parse App haves 5-6 classes. Azure translate each class as a collection on Document DB. The problem is that having so many collection (5 approximately) is very expensive (+250$/month). Do you have a less expensive approach? My App is relatively small and I can't afford to pay 300$ per month. (I’ve a budget of 100€/month)
Thank you very much

The issue names no file, test, or entry point. Start by reviewing how Parse Server maps classes to Azure Document DB collections and compare the monthly cost with the stated 100€/month budget. Done would require a maintainer-approved, concrete lower-cost approach or documented configuration change.

Written by the indexing model from the issue text.