I’ve tried to find them to no avail. I’m guessing the box sets just aren’t made anymore, but I figured it’s worth asking in case there’s some obscure one out there somewhere.
To clarify, I’m looking for a more recent Linux version. I know the older ones can be found on auction sites and the like.
No distro I’m aware of still provides official box sets and CDs. Debian still provides materials for third parties to make them, though. Most of the vendors of pre-burned Linux media have also shut down, but one that seems to still exist (and offers Debian box sets) is https://www.shoplinuxonline.com/ .