how to stop being materialistic and greedy?

i'm not sure about the context but if you look at it from the viewpoint that, you have earned/deserve the things you like, then what's the problem
or if there's something expensive that you desire, look at it as a goal and save up for that thing after a set amount of time
there's no shame in having expensive tastes but if it's interfering with your life negatively in the sense that you can't afford life necessities or you look down on other people then you just gotta learn self-control and be humble and self aware

If this was a serious question try volunteering with people who are less fortunate! I think I'd be a much worse person if I hadn't volunteered throughout undergrad.

If you buy everything in the world you wont be tempted to buy anything else!

Dude control yourself seriously

Just remind yourself that none of the material items matter. Someday you will die, and all your junk will be donated, sold or thrown away. Things that you cherished will not matter to the people going through your stuff, trying to figure out what to do with it all. Live simply, and be happy with what you have, and remember that so many don't have food, clothing, or even a home to live in.

Q: how to stop being materialistic and greedy?

A: the first step is to unburden yourself of a symbol of materialistic greed, by sending me all your popsicle collectibles. only then will you be free!!

...Die.

That's pretty much the only way.

We are biologically programmed for this stuff. Our brains are hardwired to reward us for gathering resources (and can't tell the difference between ones needed for survival, like food, and more abstract resources, like collectible figurines). There's just no escaping that desire to have things as long as you remain human.

That isn't to say we can't recognize this aspect of ourselves and make an effort to curb it. That's certainly possible, and basically boils down to willpower and diligence, a willingness to police your own behavior. But at the end of the day, even a desire not to desire things is still a desire--desire for what you don't have is simply an innate part of being human.