I've already set it up and we're running a test with 4 users since about a month now. I'm hosting it on Hetzner VPS with storage on Wasabi, backups on Backblaz

I've already set it up and we're running a test with 4 users since about a month now. I'm hosting it on Hetzner VPS with storage on Wasabi, backups on Backblaze. You're correct that storage is cheap. Compute and ram are the main costs, and I'm not sure how to quantify that until/if we run with the full team of 30 people. My current setup of 4 dedicated vcpus, 16gb ram is massive overkill for 4 people, hopefully it's enough for 30. It's currently at around the break even point compared to MS Teams. I think maybe $5 a month more expensive all in for the VPS, storage, and backup. It would be cheaper if I could run on Arm but unfortunately Hetzner doesn't have that in their Asia region yet.