Are the Royals Value for Money?

Proof if proof be needed that all things must now justify themselves, or be justified, in the language of the market, from this BBC article discussing the new figures on what the Monarchy costs the UK taxpayer. 61 pence each a year, apparently. The Keeper of the Privy Purse, Alan Reid, has loyally maintained that:

We believe this represents a value-for-money monarchy. We're not looking to provide the cheapest monarchy. We're looking at one of good value and good quality.

How long, I wonder, before we see them floated on the stockmarket?