Normally I shy away from buying pre-assembled kits of any kind but I figured Id give this one a look see. This particular kit is made by Habilis and this is their Fire Kit. You can pick these up on the Habilis website for $25.
As you can see it comes with a Forged Steel Striker and a piece of Flint, a Bee's Wax Candle, Convexed Mag Lense with a Pouch, Some prepared Char-Cloth, Cotton Cloth, a piece of Fatwood, some Jute Twine and a 4" Round Tin.
First off, the convexed mag lense is just awesome. These are fairly hard to find depending on where you are and they work the best (I think) when starting fires using the sun.
Other than the Lense and Flint & Striker, this is basically just a Tin of differant Tinders that are fairly easy to find. But that doesnt really effect my overall opinion of this kit because I think it would be perfect for anyone who is just starting out in the art of primitive firecraft. It does come with detailed instructions on making primitive fire as well as how to make char cloth.
Bottom line is this a kit for everyone? No. If you are experianced in primitive fire than youll have no problem building one of these kits on your own. If your a beginner than I think this kit is a great starting tool. I dont think this kit is a gimmick but rather a look into differant ways to start primitive fire.