Chess can be an inexpensive activity if all you want to do is play with some friends.
But if you want to be involved in more organized activities, clubs, competitions, etc, then the costs of all that organization can start to add up.
Someone I went to college with had a son who was into figure skating, they were spending upwards of $10,000 a year on equipment, coaching, practice time (often at ungodly hours of the day like 5AM), competitions, costumes, etc. He was ranked in the 200’s in his age group, and they said if he had the talent to move up to the top 50 they’d probably wind up spending more like $50K a year, and several times that for international events.
On a recent trip, we happened to be in the same hotel as several youth softball teams, who were in town for a regional tournament. Unfortunately it rained most of the weekend and the tournament wound up cancelling a lot of games, but the parents were still out for hotel rooms, meals, travel expenses and tournament entry fees.
Chess can get expensive if you start to get into serious competition, but many of the organized sports are probably a lot more expensive.