20Alan is Perpetually Poor
For sitcoms to work so well over the years, all kinds of things that aren’t normal in the real world have to exist in the world of the show. These are call sitcom tropes - the loud and obnoxious crazy neighbor (Rose, for example). But for the entire premise of
Two And A Half Men to work, you have to believe that Alan is poor.
Alan is a chiropractor in Malibu. One would assume he makes far above the median average for these guys, which is 146K annual. Even with having to pay alimony, he would have been able to live moderately comfortably for a single man.