How do I get my purchase-happy friend to stop buyinge and other friends shit we don't want or need?

I have a friend who will look for any opportunity to buy his friends something. He isn't wealthy. He doesn't make a lot of money. He just has this obsession with buying things for his friends.Not even local friends, but friends online. Steam games, alcohol, pizzas, gift cards, books, ebooks, comics, even just randomly throwing cash at you somehow. It was neat at first but it's becoming awkward. He has even admitted to me that it's 100% selfish and he only does it because buying things for people makes him feel good and he wants that dopamine hit. It's like when you buy yourself some stupid shit for no reason, but he subjects his friends to it CONSTANTLY. I would not even be here asking about this if it weren't a constant, multiple times daily occurrence. He wants to buy anyone he knows anything he can afford whether they want him to or not at any time. Having given him my address in the past was a mistake. He hoards shit FOR ME. I'll get random shit in the mail. "HEY DID YOU GET YHE THING? DO YOU LIKE IT?" even if I do, I kind of don't want to tell him. I don't want to encourage him. But we have yet to find a way to make him stop, so encouragement is the least problem.. we need to somehow DISCOURAGE him. which is hard. Especially when he gets drunk. Which is FREQUENT. Purchases are often made while he is drunk.

Dunno what to do or how to try and make him chill.