Etiquette Snob here… lol
Indeed this one of those things that can differ based on locale & family traditions
(ie in the UK the Wedding Attire for the Bridal Party is typically paid for by the Couple, in the US it is usually paid for by the Attendant themselves)
However… when it comes to Children in the Bridal Party, a lot of couples do decide to cover this cost as a “thank you” to the Parents who have agreed to “lend” their kids to the B&G for the day.
That sort is the rule when it comes to “Traditional Etiquette” and certainly what I did the first time I was married, and had a BIG White Pouffy Family Wedding… we covered it all… head to toe. The Tux Rental for the Ring Bearer, and the Dress & Accessories (socks & shoes) for the Flower Girl.
As well, we followed Traditional Etiquette, and picked up the other necessities for our Bridal Party to enjoy their weekend with us including:
Transportation from their Accommodations to the Ceremony, Reception Site, and back to their Accommodations – the cost of their Accommodations for 2 Nights (Rehearsal & Wedding) – and issued them Invites for both themselves and a Plus One for the Rehearsal Dinner & Wedding
All of these things were also extended to the Parents of the Children in the Wedding Party… so anotherwords, we paid for Accommodations for the entire family (Flower Girl, Mom & Dad, and any other children that came along… ie you cannot invite the Girl and her Parents and not include the other Brothers & Sisters). Same with the Rehearsal Dinner.
As for Destination Weddings…
Rules of Etiquette remain the same.
Hope this helps,
PS.. Ultimately what you choose to do is up to you… as with all elements of Manners & Etiquette there is ALWAYS a risk if you go against the grain… it is up to you to measure the risk and make your choices accordingly.
Personally, I couldn’t imagine inviting someone’s child to be in the Wedding Party, and my not paying “the bulk of the freight”… as I said, it is a big deal and honour, to have someone “lend” you their kids for the weekend.