I think the most logical assumption is that he never changed from back when he first moved to Washington and was vlogging constantly. I highly suggest watching some of those videos for a look at his spending habits. He goes to stores and just throws money around without even thinking about it. Buying every trinket he sees without a second thought. If he sees ANYTHING advertised on a commercial he ends up having to go and buy it. When he goes out to eat, he doesn't do it like a normal person, he ends up ordering hundreds of dollars worth of food. Several different entrees ,sides, desserts, etc. Even when he gets fast food he'll order 3-4 different things off the menu. He's also been known to eat take out several times a week, if not every single day, so that adds up quickly.
TL;DR; He lives like he's nigger rich.