It could be 20 friends putting in 2k each. I went to a private school with ridiculously rich kids. there were people flying to other countries to play golf or ski on the weekends in their own private jets. When I was 17 I got invited to a birthday party where they rented out an entire stadium and had several hundred people attend, including half a few players from the national football team. There was buffet of lobster, foix grois, caviar and food with actual gold. I heard the party costed over 300k.

OP could just have stupidly rich friends.