Many of the Usborne books are coming up Out of Print at Amazon, but most of them can be purchased new from an Usborne Books consultant.
As far as I know, the mini version and the regular version are exactly the same except that one is smaller in size.
These links take you to one of my customer’s Usborne bookstore. You can purchase other books (Usborne books are fantastic! I’ve never come across one my children didn’t love) from her at this link: https://j5127.myubam.com/330550