Opinions needed

[forgop]

Just a little scenario to see if anyone agrees with me on this or not...

Wife and I will have been married for 8 years in 3 weeks. She has a brother who is 39 and will be getting married this fall. When we got married, he was an usher and part of the arrangement was that all of the tux's were paid for and we contributed half of the cost of the bridesmaid dresses, which maybe amounted to a $50-75 cost for the girls to buy and keep obviously.

Fast forward to today, we are both considerably much better off financially, although he's now pulling in around $150k and the fiance to be is probably making $60k+ at least. They've only been together 6 months and she's asked my wife to be in the wedding. She originally said something about not being picky and wanting to allow the girls to wear whatever style dress she wants as long as it was a certain color. Now, by B-I-L has decided that he wants a specific dress for everyone to buy, which would probably be $150.

While I make a pretty decent income myself, we are living on solely my income while my wife stays home with our 3 kids(4,2, and 3 weeks old). Am I crazy to think someone with more than twice our household income should help pay for the dress if she's going to be in it in this case? I'm literally of the opinion that I'll stay home if they expect us to foot the whole bill.

What would you do in this situation?