There has to be the same rule for your children/grandchildren and his, especially if you're using joint savings to help or treat them.
It doesn't look like go feels this way, especially based on the obviously disparity over your contributions to the daughters' wedding celebrations.
If he insists on buying more than a moses basket for this grandchild I'd jump in and make it clear that you're not happy about his daughter getting more than yours, make it clear that you intend to redress the balance. Tell him that if he insists on buying the cot and pram you'll be checking out the price of a moses basket and making sure your daughter is given something similar in value to the difference, I'd even bring up the wedding and say that you're even thinking about doing something to to this up too, maybe put the cash difference in a bank account for 'your' grandchildren if your daughter isn't bothered by it.
Some people may think it's petty but children and grandchildren should be seen to be being treated equally otherwise it could cause resentment in the future. I know this from experience where my mother has 5 grandsons, the eldest (mine) has had everything he ever wanted given by my mother, my sister's 3 got less but significantly more than my youngest, who has seen/felt the disparity and when he was younger asked me sooo many times why she was so unfair to him, unfortunately I've had no answers for him. Now he's older, he's practically cut her out of his life. As they say, 'what goes around comes around' and as far as my son and I are concerned, she's done this to herself, so please, please, don't let your husband treat your 'bloodlines as inferior to his own.