I agree that the Monaco - Montecarlo part of the wedding was probably 100% or so funded by Grimaldi and there is no problem there.
Borromeo family: the bride has not much personal money (except the income as journalist / contributor that can vary a lot depending on experience and popularity), everything she's done so far has been funded by someone else (studyng, high life, dresses) and she not a large heiress as her father is a minor member of the Borromeo family as discussed previously. In addition she has another 3 sisters and a brother.
The Borromeo family may have given as present the use of their property venues (Islet of San Giovanni and Castello di Angera). But being that the Borromeo owner is the uncle of the bride and he has already offered hospitality to her sisters weddings in the other islands, I would not expect that he has covered the expenses of the bride, honestly.
We also need to remember the bill of the hotels for guests, Grand Hotel Des Iles Borromees and Hotel Majestic.
Let's come to the Marzottos then. In Italy normally the family of the bride covers the wedding dress. In this case Beatrice had several wedding and function dresses. There is the possibility that she did not pay for all of them, that she lent some of them and the designers got publicity in return.
I read somewhere that the whole bride's family was dressed by Armani. I don't think that Giorgio Armani would be happy to dress up the whole Marzotto party for free as he does not need to this, but who knows?
Some branches of the Marzotto family are affluent and successfull, others aren't.
There has been a serious breach between Marzotto family members following the recent tax scandal and other company issues. I tend to believe that those who are seriously rich and successfull stay away from the spotlight, and they are those who did not appear in any picture of the wedding. Those who need media attention are also good in keeping up appearances, but who knows really?
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Hence my curiosity