There has not been a 3 pc. ksig for sale yet, they have all been the 4 pc. Ball that most all have raved about in golfwrx. I have 4 dzn from the original release.
Go over to golfwrx, there are 300+ pages of reading material. Of interest to me was Dean Snell's comments on the ball and that Costco has been sitting on a stockpile of them but only releasing so many at a time, generating a huge buzz, and getting more memberships as a result. They were available to non members originally, that's how I got some and paid a little non members fee, but not this last release, you had to be a Costco member to actually purchase them. Slick move and I'm willing to bet they got quite a few members just based on the balls alone, and some strays too based on the other products they offer after hearing Costco members sing their praise for them.