Can you buy all 999 Power Moons?

Excuse me, I was wondering if it's actually possible to purchase all 999 Power Moons in the game? I've heard rumors that some players have managed to collect them all, but I'm not sure if it's just a myth or if there's a legitimate way to acquire them all. Is there a specific strategy or method that one needs to follow in order to achieve this feat? I'm genuinely curious and would love to hear your thoughts on the matter.