[Question] Disk Space for Lemmy and Mastodon instances

Hi, I'm new with self-hosting but managed to set up my own Lemmy and Mastodon instances on a VPS recently. However, I ran into an issue with disk space quite rapidly (which I had way too few, because I started with the cheapest, smallest package for my VPS).

Now I prepare a new setup, where I'll be able to dynamically scale disk space as needed, but this can get expensive quickly. Therefor my question: How much disk space do I typically need for private (1-3 user) instances of Lemmy and Mastodon? Are there settings, where I can limit the disk space utilization (at the cost of older stored content being overwritten)?

I would be fine with needing up to like 30-40 GB, but any more than that would be getting kinda expensive ....