My old buddy and GameTZ mega-trader Lunar had a period of his collecting career with a great concept:

This always stuck with me because everyone collects too much stuff. It’s a great way to ensure you only have your favorite games in your collection instead of a bunch of checklist-fillers and “good deals” sitting in piles on the floor cropped out of your Instagram photos.
The CQ podcast community started referring to this as the Billy Bookcase Challenge. It’s a vision of a theoretically ideal collection, although all of us are too scared to actually give up our precious bulk.
There are two slightly different ways to think about it:
Sell everything that doesn’t fit onto one Billy. Only keep your best stuff. The top few percent of items in your collection are the ones that make you happiest. Everything else is adding unnecessary stress and clutter to your life.
You can afford a much better collection if you consolidate the value into fewer items. Sell your 700 crummy NES carts for $20,000 and buy a CIB Matte Super Mario Bros., Myriad 6-in-1, and Little Samson (or whatever you think is coolest!)
This creates some neat trade-offs to think about. If you want a big top-shelf game like Earthbound facing outward, that takes up a third of an entire shelf on its own! If you want to maximize space, you can double-stack games and hide a second row. By doing this you could fit around 400 CIB NES games or 660 DVD cases, although you wouldn’t be able to display them all.
Big, stupid modern limited editions are out. You can fit maybe 1 or 2 on top of the bookcase. But tiny games are easy. You could fit the entire set of Japanese Game Boy games in their cute little boxes, maybe even Famicom if you really crammed games in there.
How much do you value aesthetic presentation compared to Tetris-ing in as many games as possible within the size limit? I don’t think there’s a wrong way to do it.
And all that absolute trash those Amiibos, strategy guides, old magazines, and third party controllers you have filling space your current shelves… Maybe that filler isn’t really worth the space in your home to begin with?
Collectors get a hit of dopamine when they click Buy it Now. They get another hit when the USPS guy rings their doorbell with their new junk. Maybe a third when they check it off their spreadsheet. Then they file it away in a box, binder, or shelf and move onto the next hit.
It’s hard for collectors to be happy with what they already have. We adapt to our collections very quickly whether we have 100 items or 10000 items. There’s always something we don’t have that would surely make us happier.
By strictly size-limiting a collection, it forces you to stop mindlessly buying for dopamine. Or at least, if you’re going to keep doing that, it forces you to sell old junk so it doesn’t pile up in a room.
Prevent yourself from telling yourself the lie all hoarders tell themselves: “Well, surely that room of old collectibles will be worth something when I retire! Maybe I’m an alternative asset investor!”