Not a fundraiser per se, but if your team is in need of show apparel, it may be worthwhile to reach out to Georgina Bloomberg’s The Rider’s Closet. They donate new and gently used show clothes to various orgs throughout the country and will usually help out school programs.
The coach of my adult eq program got a donation from her and I think all the women on our team got at least one article of clothing out of it (I got super nice ariat breeches and a show shirt, others got show coats). The couple of guys on our team had slim pickings, but we also had a lot of items that didn’t fit anyone or too many items in one size and our coach wound up selling the excess items and putting the money into the pot for our finale show so it didn’t cost didn’t cost quite as much.