I think you need to specify what level you are talking about.
I was told a long time ago that the top end competitors, who take multiple lessons every day, and travel to a new comp more or less every week, often out of country, spend $50 - $60K / year. Especially if you count the people (I met one) who paid for a Russian dance partner to come and stay here. Prices haven't probably gone up, too, so it's even worse.
But that is extreme. Like world champions and wannabees for same.
Even at a lower level, a lot of people leave out driving expenses - driving to ice, to lessons, to the pro shop, and for ladies, to the dress shops and dress makers - at about $0.50/mile total driving expenses, it builds up very fast.
Now I work at a local rink, and skate free, and am not taking lessons. I sharpen my own blades, and manage my own equipment. I bought one pair of skates about 13 years ago, and the other, I got more or less free, because I volunteered with a LTS program. I bought a bunch of runners at $110/pair for my interchangeable blade mounts, many years ago, and haven't run out. The rink doesn't pay me much, but it probably more or less covers my current skating expenses, which are basically just driving. I really should get a good pair of custom-fit skates, because the old ones are broken down, and the ones I got more or less free are too big, stiff and heavy, but I haven't. And I could use a few lessons.
I'm also doing various exercises and strength training at a local gym, which costs $315/year to belong (it includes a swimming pool and hot tub) - but it is next to the ice rink. There is another gym close to where I live, and as a "senior", in my county, I can go for free.
So basically - I'm close to breaking even. But only because I'm economizing.
I know a little girl whose parents pay for about 3 private lessons / day, with good coaches, and drives fairly long distances to get there. She also goes to the gym, and does dance and gymnastics. Let's say $120 - $150 /day. She gets nice clothing too, and is at a stage where she grows out of things. She is also dealing with a lot of medical problems, maybe because she does so much physical activity. She sees doctors rather often. So let us say $150 - $200 / day, almost 365 days/year... about $50K - $73K / year. Because of all those medical problems, she probably won't reach the highest levels, but her parents are fairly wealthy, and are willing to go for it.
In short - it all depends. Expenses can go very cheap if you want them too - and the sky is the limit if you don't.