I suppose I identify with C&V, not just because I like the aesthetics of old bikes, but because I'm cheap. So I have 5 bikes.

The cost to replace the most expensive (and not coincidentally the most modern) one is about $1000-1500, although I'm into the bike for only about $500. Most of my bikes were acquired cheap or free, then tailored to my tastes in similar fashion (cheap or free).

I sold one of my bikes off last year, mostly because a friend of a friend was looking for a cheap bike. I don't think he even rides it, but he did a handful of times. I don't miss having it; the others do the job.

This article, as Centaurious points out, could apply to anything that's done to excess, especially things that require a lot of money. I only keep 5 bikes because the investment in them is minimal. My wife can see the benefit of my riding and accepts that I have several bikes, so it's all good in our house. You have to strike a balance though; get too far out of balance in a selfish way and it will cause discord with your spouse. The problem isn't too many bikes though; it's devoting too much of your resources to selfish pursuits. That's not good for any relationship.