It has its benefits, or so I've heard. If it sounds cool to you, get it. You are certainly at the point in mentalism where you can get what you think sounds good. We can easily recommend stuff ('we' being your fellow mentalists) but ultimately it is up to you.
Too true. More than anything i'm just hoping to avoid getting stung. Many books/dvds promise the earth but deliver very little. I just like to research something before diving in and I love a good book, it's nice to pick up something with 50 something affects in, all of which are killer.
Still once in a while I'll see a trick that's going for £20 on its own and something will say it's what I want. Trrilogy for instance is easilly worth twice what I paid for it. My magician friend saw the demo vid and said he thought it would be too impractical but when I performed it for him face to face I've never seen him freak out so much. When I showed him the deck he loved it.