I bought the Tome of Fate +1 when they first showed up, it was nice to get a twist really fast. When I saw that they were adding Tome of Fate +2 and an upgrade Tome to raise my +1 to a +2 I was interested and recently bought the upgrade tome.
I ran into a couple of issues though, first I could not buy the Tome of Fate +2 or Tome of Fate (+1 -> +2) on any of my characters that had used the Tome of Fate +1. I had to buy it on a lower level then pass it using the account bank. I then tried to use it and got the error message that "You can not use that because you have already used one of equal or higher value". I suspect this is also why they were all greyed out with the message "Cannot be purchased". I tried a variety of ways to use it, on the hotbar, in the marketplace after talking to the fatespinner, on a chracter that had earned many fate points and on a character that only had 1 fate point from the Tome of Fate +1. None of them could use the fate point upgrade tome.
So now I have 2 Tome of Fate (+1 -> +2) that I can't use on any of my characters.