Comment by Telaneo

Scott Pilgrim vs. the World: The Game was digital-only, so nobody could buy a copy of the game if they wanted to, since the only places which sold the game stopped doing that, and used copies by definition don't exist.

Physical games can still be bought even if stores stop selling them, since the used marked will still be around (the game might be rare and command a high price on the used market, but at least it's possible).