I've actually purchased the item twice now. The first one worked for a while before vanishing, the second one failed to deliver. This is weird because i don't think I've ever had an object or item vanish from my inventory before.
Strangely, all of the demo items from the same store/owner also vanished with the first one.
I then tried repurchasing the item, and it said it was delivered, but the outfit was not delivered in the object/container, just an alpha. I have tried clearing my cache and rebooting. I've never had this happen before.