This item's been gone from the CS for quite some time now and I'm guessing it's due to the new wardrobe coming into play. What's going to happen to all the slots people have paid for?

There is an Outfits button in the new wardrobe. I can see all my outfits there.

I've got the maximum number of slots, but in the new wardrobe it's saying I can buy another one for 250 CSC. Looks like it's another thing that's been changed to buying directly, instead of buying and using an item from the Cash Shop. :)

all my previously paid for slots exist in the new wardrobe. Since I didn't know there was a maximum of 10 in the old wardrobe at the time, the extra one I bought years ago but which never showed before also shows in the new wardrobe. I did buy one slot direct just to be experimental in the new beta wardrobe to up my total to twelve, and this new twelfth slot does appear in the old wardrobe so it shows 11 outfit slots there, although the last one doesn't fit in the window properly.

When the outfits were added to the new wardrobe, I asked if there was a maximum, and he said that there no longer is a maximum and that I can go to town and buy as many as I like. I have filed a Ticket to see if Subeta is tracking the purchases we make on wardrobe outfit slots while it is in beta.