No they don't. The SG has gone up to £132M... that is absolutely obscene for about 2 active people... King and Queen. The others are just around on high days, holidays and photo ops. Wimbledon, Ascot, Football, let's not forget.
How Royal aides can say they are good value for money, I DO NOT KNOW.
Then we have security. Every cash strapped council has to fund security if every they do deign to visit somewhere. Estimates are that the security costs £100 million on top of the £132M they receive by way of SG. Per year. It is a closely guarded secret how much the security is, because there would be a public outcry. Under the freedom of information act, it has been asked in court by a KC how much security was over a 3 year period. They refused to comply for security reasons but how a total of security spend over 3 years would enable someone to mount an attack, god alone knows.
They do not pay all the taxes the general public pay. William refuses to disclose how much tax he paid on his Duchy £26M payout he got in the last financial year. So we have no idea.
No Inheritance tax either.