My MOH and I were just starting to talk about a shower for October.
I don't know what the etiquette would be on that, not that I would follow it anyway, ha!
I don't mind paying for them myself. I was going to bring back some items from my Mexico trip last week, but I didn't find what I really wanted, and when I did, they didn't have enough of them.
So to answer your question... just ask your BMs... maybe they already have it all planned out and you won't have to do a thing