A spa day would cost as much as the premium price yet plenty of people enjoy those, including me! You have to pay for the pleasures in your life.
Comments re the public purse already paying etc are irrelevant - the monarchy, their palaces and pageantry etc draw admiration (and tourists) from all over the world, which boosts our economy, so we all benefit indirectly, and as for the monarchy not paying death duties etc, the cost would be crippling - even for them! The monarchy is one asset we have which cannot be bought up by China etc. Lets keep it that way!