Consider what's cheaper, paying for Caddy under its current pricing structure or paying for a consultant to configure NGINX? If the key selling point of Caddy is that it makes web hosting easier to manage, but you can get around that cost by paying a one-off cost for someone to set up a free, high-performance web server, you've taken away the most of the potential benefits.

As a reference, you can see the current pricing structure for Caddy here:

https://caddyserver.com/pricing

Note that the limited time introductory price is still more expensive over a year than paying a consultant for a couple of days to tweak NGINX.

That doesn't look more expensive than consultant, looks less. That's what I'm saying, if anything I think they may have underpriced that cost. That's way cheaper than most support options I've seen.

If you're seeing companies spending $600 a day for a devops consultant, I don't know what to say other than you can get much more affordable, high quality advice elsewhere. That said, the super high wages of IT staff in some parts of the US is a frequent source of surprise for me.