Everything that I haven't bought yet lol.

Heroes 1: I would like to buy it to complete the collection digitally as it were, but there's no way I'm paying more than $1 for it, and there's no way anyone who doesn't own the game should be paying more than $0.50 for it - it is a shadow of HOMM2/HOMM3 but always goes on sale at the same price every single time.

Nebuchadnezzar+DLC: I almost got back on the hook for these games with the remake of Pharaoh, but I held off buying the remake because of bugs/poor quality, and although I still revisit Caesar 3 from time to time it would be nice to try something in a different era with a more modern UI with a more likelihood of long term support. Unfortunately it goes on sale on Steam a lot more than it does on GOG.

My entire wishlist. I'll buy those games if GOG ever returns to being a DRM-free store. Starting with their own (CDPR's) games.

When I look at my wishlist, I can sort games into categories based on the reason I have not bought them yet.

Games with no official Linux support, I am waiting until I can buy them for 10 € or less:
- Citizen Sleeper
- Everspace 2
- Gamedec
- Grim Dawn
- Myst (2021)
- Terra Nil

Expansions that I plan to buy after I play through the content of the base game and expansions I already own:
- Stellaris: Overlord
- Stellaris: Toxoids Species Pack
- Stellaris: First Contact Story Pack
- Titan Quest: Atlantis
- Titan Quest: Ragnarök
- Titan Quest: Eternal Embers
- Warhammer 40,000: Gladius - Adeptus Mechanics
- Warhammer 40,000: Gladius - Escalation Pack
- Warhammer 40,000: Gladius - Adpeta Sororitas

Games that are still "in dev", that I plan to buy when they get released for real:
- Fabular: Once Upon a Spacetime
- Songs of Conquest
- The Slormancer
- Timberborn

Games that have not been released yet:
- Frostpunk 2
- Nighthawks
- The Alters
- Warhammer 40,000: Dawn of War

Games that I think I would enjoy, but will only buy when I am sure to have some time to dedicate to playing them:
- Nebuchadnezzar
- Black Geyser: Couriers of Darkness

And that's it, there are only 25 games in my current wishlist.

I have a, personal, wishlist of about 90 games to buy on GOG, but can't right now, as I want to reduce the backlog first. When I say "personal" wishlist, I mean I have noted which games they are, but haven't put them on GOG wishlist list, because I don't want to be sent e-mails when they go on sale. (to avoid any temptation of buying them and further increase my backlog) :)

in other words, you would like Chasm: The Rift to be on sale for $10

Here I use GOG wishlist system but disabled all of their marketing e-mails, including the ones about discounts to game included in the wishlist. I don’t like advertisement, and will never subscribe to get some willingly.

Exanima - is this ever going to leave the IN DEV status (after being in it for about 8 years now)? Is it still worked on at all?

Genuine question: why would you want to buy "Chasm: The Rift" (or any of the other games on your list) in bulk?
Especially, when - as stated in your initial post - you don't buy games/DLCs because they are too expensive?

And now you want to buy 100 copies of one game for $10,- a piece?
So - $1000,- for something, that you could easily buy for $20,- (or $12,- (apparently its lowest price yet))?

Makes zero sense to me.

I really want Dead Cells (Really fan of Metroidvanias and Roguelikes/lites), but the price is so high right now even on sale that it feels weird, plus DLCs, which are expansive as well to me.
Albeit it seems an amazing game with huge content, it just gets more expansive through time - so I might wait for a big sale or an opportunity to trade.

Theres also Dust: An Elysian Tail. Waiting for a sale as well. Looks beautiful and seems to have a fluid gameplay similar to Sundered which I enjoyed very much (fluid gameplay that rival Hollow Knight in my humble opinion).

Grim Dawn Definitive Edition
Cult of the Lamb
No Man's Sky
Ghost Song
The Last Spell

They are still too expensive for me, but I also don't want to buy them because I have a lot of games that I haven't even launched, so I'm trying to resist the temptation to spend more money.

Grim Dawn Definitive Edition
No Man's Sky
Wasteland 3: Colorado Collection
The Outer Worlds: Spacer’s Choice Edition
the PathFinder games

are my most wanted right now

Apparently, yes.
https://www.baremettle.com/forums/index.php?forums/coffee-diary.25/

The devs seem to present weekly updates on their forums, like the Project Zomboid guys.

Unfortunately - just like Project Zomboid - the game doesn't seem to have a final release date.

Price
This probably the most common deterrent when there is only so much time and money I can spend. At the same time, the completionist in me wants to get all DLC. There is a degree of salience depending how much I favor a particular series or genre, being willing to spend more on safer choices than unfamiliar titles that I might not actually like.

Age of Wonders: Planetfall
Battletech
King of Fighters 13/14
Knights of the Chalice 2
Outer Worlds
Solasta
Trails of Cold Steel 4

In-development
I'd much rather wait for the finished product. Futhermore, due to GOG's small market share, there is a big risk of devs/pubs not properly supporting their games on this platform.

Baldur's Gate 3
Colony Ship
Hellish Quart
Low Magic Age

Already Owned
I already own a copy of the game on another platform, more likely on console. I'm more likely to re-buy 1st-person games since I like the keyboard and mouse controls for those types of games more than a gamepad. Otherwise, they are lower priority purchases, even at a good price.

Bioshock
Dragon's Dogma (GOG does not have latest patch in years)
Dust: An Elysian Tail
Tomb Raider (reboot)