You can't digitally buy Splinter Cell: Pandora Tomorrow on Steam anymore.
i don't think Pandora Tomorrow was ever on steam
But I'm sure there are grey market keys floating around.
there are ... but at this point they cost an arm and a leg (almost literally)
What happens if Ubisoft decides to stop selling Far Cry 2 due to compatibility issues they're not interested in fixing.
ubi already pulled quite a few older games from steam ... that's why i bought pretty much all of them when they yanked GRAW and i had to pay basically $60 to get both (and it was right after they pulled them too ... i imagine those gifts cost like $500 by now)