While skiing is intrinsically more costly than soccer and basketball, I think the high cost we're seeing here in the US may actually be more the result of low participation, rather than the cause of it.
Few eggs, hard to get a lot of chickens.
If a sport is ingrained in the culture, people would justify the cost a lot more willingly. I used to play competitive badminton. It's a sport that's beyond fringe here. But it's the national sport of Indonesia. Here, we had to pay for the court time, the shuttle cost, re-stringing of the racket. They all add up. So how do people in a poor country like Indonesia afford to play such an expensive sport? They make do. Court fee? Just play outside, learn to compensate for the wind. Shuttlecork cost? You can "re-condition" those birdies by replacing the feathers one by one. Re-stringing rackets? You don't need no machines if you learn to do that by hand at age 5 and practice frequently... I don't know what the equivalent of skiing is. But I bet there're a lot of ways to manage the cost if all your classmates are skiing. Maybe they forgo their Playstation to afford new boots?