The static site doesn’t cost anything. If it talks to a Postgres database hosted on Render, then you’ll pay for that PG db, but not for the static site itself.
As an example, I am currently hosting four sites on Render.
Two are Rails sites with databases, Redis, BG workers, etc. I pay a decent amount for those, albeit quite a bit less than Heroku.
Meanwhile, two others are static sites generated with Jekyll(?) that are pure content and require no DB. I add new content locally, push to GitHub, and deploy to Render automatically through a GH action. I pay $0/month for these two sites.
As an example, I am currently hosting four sites on Render.
Two are Rails sites with databases, Redis, BG workers, etc. I pay a decent amount for those, albeit quite a bit less than Heroku.
Meanwhile, two others are static sites generated with Jekyll(?) that are pure content and require no DB. I add new content locally, push to GitHub, and deploy to Render automatically through a GH action. I pay $0/month for these two sites.