I'm sadly not at the saturation point yet. I wish I were! But like others have mentioned, my buying ebbs and flows. Half of my problem is that I go through phases as to which sort of reading style I'm using or studying, and that can suddenly attract me to decks I'd written off before.
But I do think harder about what I'm buying these days, and try to only get decks I can really see myself reading well with. I'm (mostly) past the days of buying everything pretty that catches my eye, and I'm definitely past the days of fantasizing about the perfect-for-me-deck-that-will-make-my-readings-super-magical.
Waiting a few days or weeks is a technique that really works to deflate my intense desire to buybuybuy, too.
I'm also trying to keep and buy only decks that really click with me and "spark joy," inspired by reading
The Life-Changing Magic of Tidying Up: the Japanese art of decluttering and organizing. It pushed me to finally sell or trade a few lovely decks that would be better off with someone else.
But here's to all of you who manage to resist buying most everything while enjoying what you already have!