[redm]

My guess is that they have a manual pipeline where it requires some effort from a physical person to setup SSL. This $50 is to offset their cost of setup.

[mattmanser]

It takes a programmer like half a day to automate a let's encrypt process, maybe a couple if you want to make it really robust.

For example, these days most wordpress hosts do this for you for free.

Not that I think it's unreasonable to charge for this, just saying it's probably not the reason.