Pogo has re-released 50 previously-retired Mix-n-Match badges today. These badges cost 12 gems each and are available until July 6th, 2019.
These badges were originally released in November 2006 and March 2018.
https://www.pogo.com/challenge/find-badge.do?searchtype=mnm&sortName=expires&sortDirection=true
I'm so tempted to get some for my friend's account... but I think I'll resist. TY
(https://i.imgur.com/F1Dm5CA.png)