I've blended my own SF blend ripoff using big game fibers and flash, and it works well, but it's SO convenient buying SF blend and it's good quality with a lot less mess. The kinky muddler is my favorite streamer to tie and this stuff is essential.
I guess it's expensive bc there's nothing else quite like it and it works like a charm. Just know when you're buying it that in most cases, you're going to go through it FAST