I couldn't find the orange set for the life of me from the first series, and finally pulled a favor with someone on another board that I knew with a set. With this set, I've seen all 3 colors 3 times now, usually in the same wave it seems. I was pleased to buy red and grey at one time, then I found orange a couple days later at the same store...
It really does feel good when you complete this set. I don't know why, or if it's that feeling of how rare these once were and now you've got them... It's good having them now.