Rockstar Games (Take-Two Interactive) still sells GTA: San Andreas (The "Definitive Edition" notwithstanding). However, the original 2005 PC release is functionally abandonware. You cannot buy the original disc-based version digitally from official stores anymore.
This is the Holy Grail. For the historian: This is a snapshot of 2005 PC gaming. For the kid who lost their CD key 15 years ago: This is redemption. gta san andreas pc archive.org
5/5 – Preserving a masterpiece, one ISO at a time. Disclaimer: This article is for informational purposes regarding software preservation. Always support developers by purchasing official re-releases when the original experience is intact. Rockstar Games (Take-Two Interactive) still sells GTA: San
Most modern digital storefronts (like Steam or Rockstar Launcher) sell a patched version of San Andreas that removed 17 songs due to expiring music licenses and, infamously, downscaled the visual "heat haze" effects. The version preserved on Archive.org is often the ("gta_sa.exe"). This is the Holy Grail