I can not really "control" the game size of my PC because i simply add up any useful files which is required for my PC games to run properly, this could include mods, goodies and some rollbacks (not always but in most cases i got some rollbacks).

However... what i can surely "control" is the data on my PS5 SSD and for anyone using the same games they will have the exact same size, so around 3 TB for 65 games. My 4 TB SSD got around 1 TB left now, the game number is pretty accurate.

Sometimes i even got a backup of a prepared-modded build (basically the modded install), as an example my FF7 folder is at 127 GB and my FF8 folder at 102 GB now because of many different backups of different files in a different condition. However, this is a extreme case, way above of the majority of other games.

But even Baldurs Gate 3 is 134 GB now and this is actually low because i now deleted my rollbacks there, as i simply had no realistic use for those anymore (they was totally outdated given the circumstances). I did not even add any mods there so far because i was waiting all the time for a final version. This final-version has now arrived so... i do expect +100 GB there, at some point.

And my Cyberpunk folder is 555 GB in size, which simply is 3 different versions along with the "final legacy version" stored and tons of goodies... but still almost no mods (i was waiting for it, as well... this game should be final now). The goodie content alone is 125 GB now (including the final legacy build 1.63).

Every build is 143 GB, Build 2.13, 2.2 and 2.21 (the newest), all the other builds surely got no use anymore so i was removing it, but even just keeping up those 3 builds is huge.

So, it is very easy reaching my file size per folder, unless i only store the newest version with almost no mods nor goodies, or perhaps i only use the smallest classic games. Not the case because i adore a good game, not just a good "old" game, and in the end, every game may become old at some day... but the best of them may become preserved, with love.

https://ourworldindata.org/grapher/historical-cost-of-computer-memory-and-storage

It’s right that I own mostly "old" games and indie ones, but there are also a couple big ones like The Witcher 3, Baldur’s Gate 3 or Horizon Zero Dawn. Still, my strong dislike for so-called "AAA" games leads to only two games over 100GB, and no more than four between 50GB and 100GB.

As for mods and extra stuff (including GOG extras), when I use some they are not stored in the same place so they are excluded from my computation.

My actual collection is probably even a bit smaller than what I shared, as I only clean up old installers manually (while new ones are downloaded automatically), so for many games I have multiple copies stored.

I do not achieve "Incomplete games," lacking goodies, DLCs, useful mods, sometimes some rollbacks and whatelse. I am glad if i got everything in the same folder and as easy to access as possible with the "final intention" in mind, and every shape included. A PC game is not really a PC game, it is rather a folder with everything linked to it.

So, yes, we got a pretty different mentality there. It can be difficult calculating a size dependable on the personal approach but one rule i consider superior: A HDD can never be to big because to much space is never a issue... to less space is always a issue.

In my pretty long IT history... i did not have a single drive for which i had in mind, some years after... "this drive just had way to much space and i paid way to much for it"... this has never happened for me. It usually was the opposite "i wish i would have paid more for even more space...".

Indeed, if i hate any data... if i hate games, hate goodies, hate soundtracks... hate mods (i know such peoples)... if i hate all those stuff... there is no reason even to get a drive and perhaps the cheapest Walmart-computer may already have a drive inside which would be sufficient for, in such a case... "office only tasks". No matter what, this is NOT me... i love good bits and many bits. So, we all got different needs... even amongst the gamers. My needs is surely very demanding.

Just so you get a better idea of how I handle storage: I use 1 SSD + 5 HDD.
- 256GB (SSD)
- 1TB (HDD)
- 3TB (HDD)
- 4TB (HDD)
- 8TB (HDD)
- 12TB (HDD)
The 12TB HDD is the one dedicated to video game archives storage.

Of all that, a bit less than 16TB is currently used for archival (games, music, movies, etc.). Leaving me plenty of free storage space for the coming years.

I do by the way have mods, goodies and stuff put in the same directory than the base game installers, but by using symbolic links I have an additional arborescence including only the GOG installers (this one is kept up-to-date every night thanks to LGOGDownloader). This is what I used to compute the size I shared earlier.

I have similar arborescences for my Humble Bundle games (200GB) and itch.io games and games-adjacent stuff (1,3TB). These are kept up-to-date through automated tools too.