There are certain things that should just always be available.
Army builder sets
The Original He-Man
The Original Skeletor
The stands and army builders should always be around for the reasons you stated.
He-Man and Skeletor should always be around to help draw in new collectors. As the two main characters and the most recognizable, they should always be there. Someone who hasn't begun collecting may be more encouraged to start if they can get the two main figures at any time without having to go to the secondary market.