We run Metabase on a 2GB VM on DigitalOcean, costing $15/month, and using the DO's Postgres cheapest plan (still pretty expensive imo). It's a JVM app so using quite a bunch of memory, 60% atm. So total cost of Metabase is $30 per month. We could definitely just run Postgres on the same VM to get the cost down.
As for web servers, you're totally right. At feeder.co we serve 25 requests / second (on Rails) per VM (we use 4 web servers and one loadbalancer) and we're still database constrained. They are $20 per month and the 4GB 2VCPU "basic" plan.
Hardware is insanely fast nowadays, and it feels like we forget to realise it sometimes.
For a relatively small scale project (5K users) I am running metabase using my production postgres* on a free heroku dyno (Metabase even have a 1-click deploy for this). Takes about 30 seconds to wake up, but the price is unbeatable. I don't get any of the scheduled features ofc. Would recommend for keeping costs low.
*using a heroku standard-0 db, so $50/mo with relatively good performance
As for web servers, you're totally right. At feeder.co we serve 25 requests / second (on Rails) per VM (we use 4 web servers and one loadbalancer) and we're still database constrained. They are $20 per month and the 4GB 2VCPU "basic" plan.
Hardware is insanely fast nowadays, and it feels like we forget to realise it sometimes.