This is my son’s hobby as well. He doesn’t go to as many as you, but this year he has attended about 50 shows. He and his friends have flown across the country to follow some of their favorite groups on tour for a week or so. (Which is impressive, because they all work full-time.) I think going to concerts and staying in hotels in NYC and Boston throughout the year to see them is his main entertainment expense.
That is one of my hobbies as well, but I’m not quite as invested. I prefer to dive in tropical locations (which involves flying there), and typically rent much of my gear (including BCD, regulator, and tanks). I do have my own mask, fins, snorkel, dive computer, wetsuit, safety gear, and mesh bag. For a while, I was taking a dive trip about once a year, but now am only doing one every 2-3 years. Due to this infrequency, I figure it’s better to have someone else maintain the BCD and regulator. But I have considered buying my own at some point.
My main hobby, though, is downhill skiing. I usually ski about 25-30 days per year. It’s a fairly expensive sport, including the gear (boots, skis, poles, helmet, goggles, jacket, pants, baselayer, etc.), plus maintenance costs (i.e. ski tuning), lift tickets, travel expenses, etc. This year, I’m doing two flyaway ski trips to Switzerland and Banff with two different ski clubs, plus another week-long trip to Maine. I will probably spend about $10K this season.
Other hobbies of mine include cycling, which is mainly expensive for the initial purchase of bikes (road and mountain) plus ancillary equipment, but I typically get many years out them.
Finally, I like to hike. The gear for this is comparatively inexpensive, including hiking boots/trail runners, day pack, hiking poles, and the ten essentials. I also do some overnight backpacking and canoeing, and that is somewhat more expensive.
One of my biggest issues is where to store all of the above. I have a spare bedroom which is basically a gear locker.
ETA: This is one of my son’s hobby as well (and a former hobby of mine). He builds 1-2 large sets every year, and has been doing this for the last 20+ years.