It’s worth checking if your instance accepts donations to defray running costs. E.g. mastodon.social gets funding from the Mastodon Patreon: https://www.patreon.com/mastodon
There are also interesting instances like social.coop that are run like a cooperative – you join and are expected to donate monthly, as little as $1, and in return you get democratic control over the instance. It can be a cool incentive to "donate"/invest in the instance.