My mother-in-law told me to buy something and forgot to pay. Actually, it's only a few hundred dollars, but they don't usually buy things for us. Besides, the key is this.

They must think they are elders. You should give them money, but you are not going to. If you say it, they will definitely say that you are stingy and unfilial to your elders or something.

I think it mainly depends on your husband's attitude. If your mother-in-law and uncle can still be filial to you, are they financially okay? If they treat you badly, that's another matter.