I can't speak as to whether the 12FV is a limited edition or not; or, what a fair value for one is. But with respect to fluted barrels, the purpose is two-fold: The fluting increases the surface area of the barrel which is supposed to increase the speed at which it cools. In addition, because you're removing metal, it lightens the barrel. Just how significant the weight loss and accelerated cooling is, well, you'll have to talk with an engineer about that.
I have a left hand 12FVSS in .22-250. The flutes cover about half the length of the barrel and don't look as though they remove an appreciable amount of metal to make it feel any lighter. But nevertheless, it's a shooter. Bull barrel is heavy and plastic stock is light, so it's balanced further forward than I care for; but, I just had it out to western Kansas earlier this week and it was he** on prairie dogs!