I haven't had luck with this type of duplicating. Last year, I bought my first jeans in many years, so I bought two pairs. They felt great and looked really good on me. Well, since you can wear jeans a few times before washing, I found that I never really needed the second pair; the first pair was available as much as I wanted them. I have plenty of other types of bottoms that I like to rotate with said pair of jeans, so it just isn't an issue.
I also bought a second white tank from BR because I finally found one that fit me! That too sits in the dresser, because I find that I have enough other layering pieces that I like to rotate along with it, so availability is not a problem.
I guess what I would look at in your case is, do you have enough other bottoms to rotate with the PJs, such that you won't miss not wearing the PJs if they are in the wash? Is having two pairs of the PJs going to make you feel like you *have* to wear them, when you would really rather wear something else? It seems to me that you like a lot of variety in your wardrobe, because you often post K/Rs. So you do a lot of shopping and are always looking for things to add to your wardrobe (at least this has been my impression). I think that maybe it would be better not to duplicate simply because it will leave you room for an unexpected purchase that you might like just as much as these jeans. Variety is the spice of life, I say. :^)
