The latter is a true hypothetical as US law prevents charging different rates to different users for the exact same product/service.
It would be a slam dunk lawsuit.
You can still offer discounts (airline tickets, Adobe, etc.) or negotiate pricing (cars, etc.) legally.
But, it is illegal to isolate someone and charge them more without justification as in OC's example.
So yes, Facebook charging a single person $1k/year is a true hypothetical. It couldn't happen legally in the US.
If Costco charges $1k for a bagel and gives it away to everyone for free except insists on you paying, that's a problem. You're not allowed to isolate discounts based on race, gender, etc. So Costco would have to have a pretty creative reason for making you pay and no one else. It wouldn't hold up in court and it would be price discrimination.