I'm very glad you used the car analogy, Addison, because that's more or less the high ticket item I use to denounce the absurdity of it all: "Do you realize this damn bass cost as much as a car?!" If it can't drive me to the west coast and back, I simply can't justify it. If I were a millionaire, however, I might not think twice about it. As for owning it, I've used my own mortality theory to keep myself from making too many costly mistakes.
We don't really own anything, we simply rent it for the duration of our lives. Then it either passes down to your loved ones or it goes somewhere else. Whatever the case, you're looking at fairly limited time left to play the instrument, and my logical yet debatable reasoning plays out like a classic Abbott and Costello routine:
1960 Fender Jazz Bass: $28,000?
Age: 46
Life expectancy: 85 years if I'm lucky? That would be 39 years of life left, or 14,235 days. But wait, how many of those years/days will be quality days? Might I lose my ability to play by 78 due to arthritis, etc? So let's deduct 7 years. Now we've got 11,680 days left. Realistically, how many of those days would you be able to devote to playing the instrument due to life responsibility, vacations, etc? Maybe half? Now we're down to 5,840 days left, or 140,160 hours. But clearly you won't be playing it for 24 hours every single day either. Let's say the average playing time is 2 hours per day. Now you're looking at only 28,032 hours, or 1,168 days left. There are probably some other deductions I'm leaving out, but at the very least it will cost you:
$24 day or $1.00 per hour to own this bass! 
Here's the inspiration for my math.
http://www.youtube.com/watch?v=u3hIMv0lklA
