You can always pirate old games if you know you will never buy them. I used to buy (10 years) old PC titles (AA) from my local 2nd hand market, but then I noticed most of them required connecting your account to activate the game. And that is only valid for 1 account, meaning my purchase was absolutely useless. Next thing I did was to download a pirated version, and it worked smoothly on my linux machine.
I've found that some old PC titles are available on Steam, DRM free (if you're willing to futz with the install directory -- they're running open source game engines and proprietary vintage assets; you can just copy the assets out).
Typing this reminds me: I should look into switching to GOG for such purchases.
And even if they’re not, a lot of games (used to) use Steam’s DRM and then never actually called the extended license check APIs. That’s to say that a lot of times the same “steam_api.dll” that pirated games have may work for a bunch of games.
I found that out a few years ago when I tested out virtualization graphics performance and wanted to avoid installing full Steam every time for my (legally purchased) games.
