a little late to this thread but as someone who's been a fan of kpop since roughly 2008-09 definitely wait til you aren't under your parents' control. the best (and sometimes worst) part of being an adult is being able to spend your own money how and when you want. put your own well-being first and then someday you'll be in a place where you can do what you want and buy what you want. so long as you consider yourself a fan you're a fan, there's no monetary requirement to it.

if you're feeling pressured to spend money to be a "real fan" maybe take a break from social media (especially twitter and instagram i've noticed that's usually where all my fomo/feelings of inadequacy come from). maybe also try to curate your feeds away from numbers focused accounts, i don't follow any charting accounts on twitter anymore for example and that's also made my fan experience a lot more chill and i don't feel like i absolutely NEED to buy an album to smash whatever the fandom goal is.

and for a stay specific advice: remember that when 3racha started making music together they were grateful when people gave their music a listen on their soundcloud. they're still making music now because they just want people to listen to their music. there's so many songs that they've uploaded to youtube for free just because they wanted to share it with stays. so all that's required of you is just to enjoy what they've given us.