@Baracus250 @TrevKiwi
https://store.steampowered.com/app/1250410/Microsoft_Flight_Simulator_40th_Anniversary_Edition/
The only things you can currently purchase on Steam are the base game editions. It is unlikely that marketplace items would be additionally listed on Steam because that would defeat the purpose of having the in-game marketplace (i.e. The marketplace is operated by Microsoft and is cross-platform).