I think this is a fair comparison.
Casspi (and MANY other SFs out there) are like 2009-2010 Honda Accords. Dependable, fairly new, not overly flashy but comfortable. You won't win any races or car shows, but they'll get you down the road fairly efficiently. It's a car that most people, w/ a regular 5 year loan, would owe about $15-20k on.
RJ is like a 2003 Corvette w/ a bad motor, one window won't roll down and the AC works half the time. It looked real good about 5-6 years ago but won't perform like it used to now (and in RJs case, never will again). Add to that fact that the Spurs owe about $30k on it and you see why he's fairly untradeable.