Everyone has different financial situations and different concepts of what is important or not. This is not something you should be discussing “after” engagement where disappointments can sour things. These are the things that both young man and young woman should be discussing during dating and both sets of mechutanim should discuss when they meet. Even the shadchan should know something before setting up a couple.
A young Kallah whose sisters all received a list of gifts from their chassanim and gets very little might feel very uncomfortable, unless she is prepared in advance and realizes that the young man and his great family is really all the “gifts” she needs, and everything else will come in good time.
One should try to keep things even between their children and never show favoritism. Nor should they try to get more for one child than another. But this is also a reason why things have gotten out of hand. At times, families are so excited with the first shidduch that they just pour on the gifts. Then comes the next shidduch and they have to keep up…….
If you buy one daughter-in-law a 2 carat stone, you can’t cry poverty down the line. Keep in mind what you are doing when you start out. What you do for one you will have to do for the others.
On the other hand, know what you are prepared to do and discuss that with your kids so they don’t promise things you can’t afford to deliver. Make sure your son doesn’t borrow a Lexus for his dates if you don’t want to give the impression that there is more of that to follow.
When my daughter got married (we have only one) we were happy to buy him the gifts. He didn’t have an Esrog box but my boys did so we bought him one for Yom Tov, he was shocked. Then came Chanukah, he didn’t have a menorah but our boys did so we bought him a Menorah. Again he was shocked, he didn’t expect it. When my boys got married, they had all those things already so we didn’t expect such gifts from their in-laws. Actually we didn’t expect anything. My daughter got a bracelet, ring and watch. So we bought our daughters-in-law the same according to their own tastes. We didn’t want them to have less than what my daughter got.