I paid for my op, and I go to the hospital every two months or when I feel I need a refill. Yes, it costs me money directly but having lost 30kg I feel it's worth it. I need to lose another 50kg and could only do that with the flexibility of private healthcare.
Unlike the NHS if I ask for an appointment I get one instead of waiting. That said, there might be an almighty bill this month: all the more encouragement to keep losing!