Congrats! Good luck. Ignore all the angry people they clearly have no idea what it's like to try and make a living off this stuff, just entitled spoiled brats. Not to mention the salary that most developers make, paying $25-100/m for software you enjoy is not much. IMHO if you can't justify the price, then don't use it.
It's not $25-100/mo, it's effectively $50/mo per instance of Caddy, including your local development machine: https://caddyserver.com/pricing Running three static sites in their own containers, plus a fourth Caddy as a reverse proxy, and your laptop? That's $250/mo. Is a buddy of yours also working on one of those sites? Oops, now you're at the $500/mo (10 license) tier.
I regret to inform people, but the world isn't free. Open source is great because it's a low barrier for people getting started with a business or project, but if a company benefits from it they should pay.
This sort of duel license fragmentation is unfortunately the only option for people like us trying to make a living from OSS.