I got out of collecting for a few reasons, some of which have been mentioned above by others.
1) The sheer lunacy of pricing took a LOT of the fun out of collecting. Supply & demand plays a natural part in it, as most of the items are long since being on retail shelves, with an ever growing and hungry audience for the. That much I can handle. There's an artificial bs side to it though, which I've trouble with. "It's old, therefore it's worth a fortune!" This can be seen directly when observing PAL pricing versus NTSC pricing (in general, not in all cases). NTSC is usually much, much cheaper than the artificially inflated PAL pricing, wven factoring in higher shipping. So yeah, the thrill of the hunt is becoming harder & harder to experience.
2) Collecting because it's cheap/for the sake of it - I was a big offender with this. It almost became compulsive, and very much everything I bought would be sent to storage, & never enjoyed. Boxes & boxes of stuff that I'd get to "some day", bargains I couldn't pass up because they were bargains, spreadsheets & spreadsheets of all the items I had in storage....nah, that's not fun, not even close. I'd a thankful epiphany one day that I'd miss none of this stuff, if it wasn't there.
3) Space - very, very little room to use what I 'd bought & collected. An evergrowing pile of retro goodies, in an ever decreasing circle of space. It's no fun when you've to take the morning off work to dig out that console you want to play that game on, and another day to put it back when you're done. It's a hard habit to enjoy when you don't have the room for it.
4) Emulation - The answer to most of the above problems for me. Yes, a compromise, but given the difficulties, and quality of the result, a damn worthy one in my case. I'm not into millions of different emulators, needing a mouse & keyboard to get going...ala the late 90's golden era of emulation. So when I discovered Launchbox, it changed everything. Couple that with Retroarch running underneath it, and it's literally select the system you want, select the game, & just play it. A bit of time invested in learning about filters, overlays, and display tweaks, has given me visuals that close enough to the real thing (I say that as an ex-purist, who had a penchant for RGB scart cables!), that it matters not anymore.
I've kept most of the juicy bits of my collection in one medium sized container, just to have because they mean something to me. Most everything else though, is gone. Ironically, I'm playing more games today that I ever did while collecting. So for me, the transition from hoarder to person who plays games (not a fan of the term gamer), has been a happy one