That is a nice old box and belongs to someone who can appreciate it, Cajun musical history and the culture in general. It is most definitely not a toy. If you are not going to play the music, please sell it to someone who will. It also isn't a decoration.
That's little more than a modified Hohner 114. It would be appropriate for a child to play and depending on how well it plays, I would not see it being valued much more than $200-$500 which is very cheap for an accordion.