Surprise-O-Matic, is it... A scam?

So, every time I have more than 1.4M blings I go to one of the Surprise-O-Matic's and try to get some of the rare pieces, but so far I have 6/12 on the Itzaland one and 2/18 on Florawish... Anyone has all of them? Is there a better way to do it so I can collect all of them? How many times should I try it in one day?