Assuming dapps start hot-seating their users through a handful of accounts (

I think that this is the way many dapps will do it to keep resource requirements down and many there are many creative ways to do this.

If demand shot up and people were paying $50 each, would you sell?

definitely :D
In a couple years though, if I am able o set up a full onboarding for my company or similar, the value of it is likely more than the seat itself.

Sure, I have 500 now, but that doesn't mean I can snap my fingers and generate another 500.

I am going to keep creating as long as I can.