Anytime anyone asks how many I have and why, the basic answer I give is that it's because I am a collector of tones.
With that said, I have what I have mostly because I can, and having a steady adult income with liquid cash certainly helps. I do try to sell or trade something before buying another to keep it mostly within reason. I have several that I'll never get rid of because of being rare and almost irreplaceable, but there's a few that could be sold right now and I could turn around and buy them again down the road without much trouble.
My wife doesn't totally understand all of it, but the last time I told her how many are floating around she said, "At least it's not drugs!" There's WAY worse things I could spend money on, and at least I buy things that do hold enough value in the event they need to be sold. I've also done enough side jobs and gigs that pay for it all outside of my actual work income. It's much easier to justify when it's not coming from our joint income that pays the bills and feeds our bellies.