Which type is most rare – Eyes, Eye2s or Promotionals?
Eye2 color combinations are probably more rare because their production time was much shorter. Eye2 were around for only a few years before Karsten decided to quit manufacturing the duo-colored balls. Promos should be the rarest because they were usually balls that had some type of quality problem. Promos in the common colors are very easy to find. Karsten provided lots of Promo balls that courses could use for their junior programs.
