Tiers based on seats doesn't seem all that different. Flipper Cloud seems to be roughly $60/seat/yr but only buyable in fixed chunks, meaning some pay as much as $499/yr for 1 seat, others pay $50/seat for 10 seats, others pay $136/seat for 11 seats, etc.
So now, as a business with 10 users, I still have to decide if my 11th new employee is worth $1000/yr for their seat, if I should kick someone else off and give it to the new employee, etc...