So my fiance and I really don't want our bridesmaids and groomsmen to have to pay for their dresses and tuxes because we love them so much and we are close to all of them and know that they will do anything for us. Is the wedding party supposed to pay for their attire? Or do the bride and groom pay for it? Would it be inappropriate if we went in half way with all of them?
The "proper" etiquette thing is that everyone pays for their own clothing. The bride and groom try to be considerate of their guys and gals' budgets and pick dresses and tuxes that are reasonably priced.
If you want to help pay for some of it, that is generous of you but not required. Do so in a way that doesn't sound like you are saying "We've got much more money than you have, so we will buy your dress."