@honeymango I just got Mastodon running on a server at home. I used an Nvidia Jetson Nano I had lying around, and it runs Ubuntu 20.04 LTS. I got a new domain from Namecheap and signed up for SMTP service with Mailgun. I followed the installation guide at
https://docs.joinmastodon.org/user/run-your-own/ and it was straight forward. In total I spent $12 for a year’s worth of domain registration and that’s it. The Nano was $100.