Somebody tried to calculate this over at Yahoo Voices. This was their awesome synopsis:
How does Charlie afford this luxurious lifestyle? A quick look at the
MLS in Malibu reveals that even after the recent housing downturn,
Malibu beach houses cost anywhere from $1 million to $6 million or
more. A million dollar mortgage at 6% for 30 years equals a $6000
monthly payment, give or take. Charlie's sports cars set him back a
pretty penny, too - $200,000 is a conservative estimate. Daily
housekeeping services probably run $500 a week. As for the liquor and
ladies, who knows? Though Charlie always has cash on hand, I bet
credit cards (and credit card debt) come into play somewhere along the
Charlie has had quite a bit of success as a freelance jingle writer,
and when he "ran out of money" in one episode, he began writing
children's songs, which was supposedly a very lucrative venture.
However, even successful jingle writers don't make that kind of money
- for instance, JinglePeople (a freelance jingle company) is offering $45 an hour for jingle writers - not chump change, but not enough to
buy a sports car and a Malibu beach home, either. Charlie must be
racking up credit card debt in a big way!
Although Charlie hasn't worked a 40 hour week in his life, let's give
him the benefit of the doubt: a 40 hour week at $45 an hour is about
$93,000 a year, or $7800 a month. After taxes, that's about $5000 a
month. That means that Charlie's home alone costs him more than he's
bringing in. Add a $4000 monthly car payment, and Charlie is $5000
underwater every month. He better have an excellent rewards credit
card with an extremely high limit!
Unfortunately, credit cards alone would never support Charlie's
lifestyle. Here's hoping the children's songwriting business pays a
LOT better than the jingle company!
Based on that information, I call scam!
Based on the (wonderful!) discussion below this answer about the types of money jingle writers earned, I've done some basic googling myself. This article details some of the factors involved in determining a jingle writer's pay. It finishes by stating:
If commercials aren’t using original jingles or scores, they’re
licensing previously released material. On average, a songwriter can
earn $5,000 to $10,000 for a low-budget commercial, $10,000 to
$175,000 for a medium-budget commercial and $100,000 to $250,000 for a
high-budget commercial. For well-known songs, the rates can exceed $1
Charlie certainly didn't have a well-known song, just a very good set of jingles. Therefore it's plausible he could have earned up to the hundreds of thousands of dollars - but it's still a stretch considering his lifestyle and house.
I'm sticking with scam for now! (Especially since it explains why he faked his own death to appear, changed his identity and popped up again debt free on Anger Management :)