who pays...
Considering that the Crown Estates (which were given by the royal family to the UK people/Govt) earn 100's of millions a year for the govt/british people, and are worth billions in asset value; the payment of the tiny civil list (40M - of which most goes on salaries of staff - good for jobs, and maintaining palaces - good for heritage) and perhaps the odd 10/20 mil here and there for a wedding is pretty insignificant....
Or perhaps the govt could swap it back - no more civil list/public money on protection etc of royals, and the royal family get the crown estates back to spend as they see fit.....
I personally hope they have a huge wedding that everyone can enjoy/feel proud of. Best wishes to them.