In Marvel merchandise why is Bucky Barnes stuff so rare to find?

[DodgerGirl]

I collect everything Marvel and I've noticed that when it comes to merchandise of Marvel they make stuff of the main heroes like Iron Man Captain America Thor Black Panther and Doctor Strange but one Marvel hero you never see merchandise of is Bucky Barnes and I can't figure it out. Because when Falcon And The Winter Soldier first came out Bucky Barnes was seen on action figures to plushies and more. But now that Falcon And The Winter Soldier was finished Bucky Barnes merchandise is now scarce to find and it tells me that he is an underrated Marvel character for merchandise now just like Vision is. Is Bucky Barnes merchandise the more scarce of Marvel merchandise?