Our band also orders gloves and sells them for $3 a pair. I buy several, because my absent-minded 16 year old loses at least one glove every two weeks.

They are just cotton gloves, and come in small/med/large. Our uniforms also have gauntlets and that is where they keep their gloves when they are in the stands. We also have to buy a beret, which they wear in the stands. Our hats are bearskins, and if they wore those in the stands, nobody would be able to see over the person in front of them. So, they shove the beret (red wool with the band patch on the front) inside their bearskin, and just take it out when they need to put it on.
Freshman year is more pricey than other years: you need to buy gloves, the beret, the red band t-shirt that they wear under their uniform, a garment bag, and shoes. The shoes need to be black military style shoes. No seams, and need a square heel. They have to shine. I bought my DS's freshman year, and thank GOD they still fit! They were $80!! He does wear them as dress shoes with black dress pants from time to time, but still!
After you buy all the basic stuff, it's only a uniform fee of $10 a year (for drycleaning). We have a band seamstress who hems all of the uniforms and does repairs. She maintains the uniform closet and does all of the fittings. She attends every band function and goes on every trip. She is a whiz!!
On non-trip years, the fair share is $175 and that covers transportation to away games, and other stuff. Trip years are crazy. They went to Disney in February, and that trip was $1500. They are going to Hawaii in November, and that trip is $2500. The band directors made it clear that they understood if you needed to choose one trip over the other, and there are some kids who did just that. For us, though, both were such an awesome experience that I couldn't make him choose. It was our choice to sacrifice in order to send him on both trips. We do some selling (right now, it's pizzas and mums), but you can only ask people to buy so much. My parents have been great about giving him money towards his fair share...they are awesome!
My DS12 is in 7th grade this year and in the MS band, and that's also an expense. We pay a $25 uniform fee for him, and the trip this year will be $305 for ONE night. They take buses, so only go as far as they can drive in two days. Last year they went to Pittsburgh. I heard they are going to Baltimore this year. They participate in the Music in the Parks competitions. Of course, this year, he will also be in Orchestra and Jazz band (he is a percussionist), so there are added expenses of dress shirts for those.
Yes, being in band is expensive...but I would not trade it for anything! In general, band kids are GOOD kids, and they have both made great friends. Most of their friends are the over-achiever, honors types, which is a good influence on them both. If I had to pick one thing for them to be involved with, band would be it!!