If you have the money go for it. If your able to come up with between 2 to 3k for sudden repairs at any given moment you should be fine. If it would be a stretch for you to do that you might want to consider another car.

Not sure that a 140 is really an appropriate car for a 23 year old though. I remember how I drove when I was 23. You might be happier with the smaller car. Even though its bigger its no slouch performance wise. I had to follow a guy at the office with a brand new 300z who wanted to show off and was weaving through traffic at high speed trying to loose me. He was quite annoyed that no matter what he did he could not loose the big black 140 sedan following him.

The 140 is a great long distance cruiser. My 140 used to be an every day driver but has been spending more time in the garage due to the really small parking deck I park in downtown. The 140 fits fine in the deck but with 3 other cars and the prospect of door dings its not the car I like to leave in a small parking deck at the mercy of people trying to park SUV's in close proximity.

Personally if I were 23 again I would get something cheap and fun. An older BMW 3 series or a late model Porsche 944 or Porsche 968. I recently have rediscovered driving all over again with a cheap little car with perfect 50/50 weight balance and a rather surprisingly powerful 4cyl engine.