How do they justify it?

I went for a check up at the dentist today, and although I fully support the NHS (National Health Service) having worked in countries where there is no social welfare, and people have to work until they die, I do wonder how government justify the charges sometimes.

I am lucky enough to now be on the books of a NHS Dentist due to my status as a Stay at Home Dad, but even so, today's visit had me in the dentists chair for no more than 3 minutes and I was still charged £17.00, which equates to £340.00 per hour. I appreciate that they have overheads and running costs, but would it not be better if the 3 tier charging system was sub-divided based on the amount of time spent in the actual dentists chair. Or would this over complicate things and lead to a rise in administration costs.

Anybody else have similar experiences to comment/grumble about?