Most of what was said can be applied to any hobby that involves collecting. I've also gone the, substitute for alcoho,l path. I used to drink a 26er (a fifth, in the states) almost daily. By not drinking, I have at least a hundred bucks back in my pocket per week.
That's where buying CRKT knives started. I never planned to EDC any of them but they do have unusual designs. (BTW I'm trying to find a Kershaw E.T.). It was a way to reward myself, for being good, without spending stupid money. Over time the knives I don't need but do buy have gotten slightly more expensive (a venom green Izula? What was in my head?).
Now, it's a once a month thing for a few hundred. But the nice thing is that since I have my favs, I only carry the knives for a day or too to show them. So my core EDC's are the only ones that really show wear. Which means when it I do sell something it's almost mint, and hopefully long discontinued and rarer.