I’m in NY- what is it like elsewhere? Any non-school sports are obviously on your own.
There's no late bus at my kids school, nor was there at mine when grew up. In fact, I don't know of any district in our area that runs a late bus. When I was growing up, I didn't get to participate in many after-school activities because I didn't have transportation. I currently work from home so I'm able to handle transportation for my kids.
Our school has a pay-to-participate fee of $80 per activity per season. Some activities have an additional fee. There are usually some fundraising opportunities for the additional and the booster organization offers help in cases of financial hardship, but I don't know what or how much help. I have experience with cross country ($0 additional fee), track/field ($100/season fee--although the kids do get a windbreaker and the coaches gifts come out of that), and hockey ($1500).
Uniforms are usually borrowed from the school, but sometimes there are exceptions. Again, my experiences are with cross country and track (uniforms reused between sports -- boys get a jersey and shorts; girls get jersey only and have to provide their own shorts. I'm not sure why the difference.) Hockey (school provided jerseys and a cover to go over hockey pants. Kids had to buy uniform socks. Kids had to provide own pads, helmet, etc.). My daughter's planning to join marching band next year. I believe the school provides the main uniform, but we'll have to buy specific band shoes, as well as the "summer uniform" (shorts and a polo shirt).
Any overnight trips are student/booster club funded, not school funded at all.