As a huge TCP fan, I would like to say hey anything with Sprinkle. However, I also realize that you?re trying to get the most bang for your buck. I think A Bear Good Year is a great multi purpose set. You can use it year round for many different occasions.
As far as cut-ups go, I'm probably not going to be as helpful. Some of the most versatile are the new Queen of Hearts, Icing, or the clouds border.
I agree with Julie. Play along in the challenges. Alma is one of the most generous company owners out there!
Welcome to a great stamp company!