Posted by: @starkat

Now that people collect these things and tend to want to take care of them, do they last longer because they care or do they last longer because they are made with that in mind?

I don't have any extra information about this, but a few thoughts. Funnily enough, the Narnia episode and the Mary Poppins Prop Culture episodes are the only ones I have watched. But I would imagine that it is a bit of Column A and Column B. With movies that are made with a large budget, perhaps the costumers take extra care in the quality, because the movie is of a genre that could create a legacy. But would taking that extra care in producing them require additional money in their budget? 
I wonder if the movie studios now plan which of the items will be archived. 
I am guessing that the care put into the keeping and restoration of items would be from day one now. Although maybe I need to watch more Prop Culture episodes to find that out! ? 

That would make sense. Though with how hard kids in general are on clothes, maybe the kids movies have that planned from the get go?