Brand new Blizzard hardware is expensive. A simple BVision graphic card for the BlizzPPC costs almost the same amount as the promised PegII+G3 mobo. A 060 Blizzard PPC to that is more expensive than the most expensive AmigaONE available. (One may correct me on these numbers, I refer to the prices when I bought them, but back then there was no Peg/AONE available)
As to is it worth it? If you want to keep your original Amiga, and not interested in either AmigaONE, Pegasos or X86 solutions, it definitely worths the enermous price.
Compared to a stock Amiga, or even to an accelerated one lacking a GFX card the BVPPC060 combo is breathtakingly fast, you can play PPC games, use PPC emulators of many games console, utilize PPC in rendering with Tornado 3D, and some ppc modules exist even for ImageFX, you can listen to MP3s with minimal CPU time, watch movies, even smaller divx anims with acceptable playback speed.
The BVPPC060 combo is the ultimate for the A1200. :-) It makes your system fly compared to an AGA system, and for most CPU intensive tasks there is a PPC alternative, which will leave you with an almost free 060 CPU to do what you like :-)
If you can, try it out somewhere, then you will see the difference yourself :-)