In laws being unsopportive.

Hello all, I have a question that is quite...difficult. My Fiance is struggling because my family doesn't have too much money and they are helping us in everything they can and more(money, logistics, etc), and his family has quite a lot of money and they didn't help on anything at all. They even suggest to take things out of the way that are not necessary according to them(decorations, not invite my family, etc). He is suffering a a lot because of this family indifference. Also, they are always telling us that they will help us with anything, but in the moment of needing them they will retreat. Any way of telling them, softly, that their behaviour is hurting their son and making things really difficult? Thanks