[danjac]

You can deploy Docker containers to Heroku. I've done this (just requires a simple heroku.yml file and heroku stack:set container). If the project grows to the size where Heroku's costs become prohibitive, I can easily switch over to Digital Ocean with some tweaks to the docker config.

[manigandham]

Why not just save the money and start elsewhere?

[danjac]

Most of my side projects never go beyond needing heroku free tier, and if they gain some traction the basic tier is usually sufficient.