> And what happens if your domain gets popular, are they going to just jack up your rent from $25/yr to $500/yr or more?
As long as your domain is in the standard fee class, aka non-premium, they can't target it for a price increase if it's a gTLD. They have to raise the price of all standard domains at the same time.
Everyone will tell you they can't reclassify a domain from standard to premium, but that's not technically correct. They can change the classification to whatever they want, but they have to charge you standard renewal fees if the domain had a standard classification when you registered it, as long as you haven't let it expire.
I created a website that has some info about domain reclassification.
https://tldrisk.com/beyond-basics/reclassification/
