Hi Paolo, these are such interesting smurfs. I was very lucky to watch the auctions these smurfs sold in, so exciting! As for price, well the figures that I quoted are in USD which at the time was much stronger so in "real" terms their prices would be even higher in Todays Euro or GBP!
They were sold by a very well known collector (at the time) who apparently used to work for Schleich and sold off an incredible collection of very very rare smurfs and the general opinion at the time was that these were real. These smurfs were sold to different people so the person you are in contact with didn't have these ones. As for how many of these exist, as far as I know no one knows.
The fact that fakes of these can be produced to me is very worrying because apart from anything else, I am sure it would effect the value of the real ones and these days so many smurfs are being faked purely to rip people off.
I have heard stories that the current owners of these three have declined very higher offers (thousands) to sell them so whether we will ever see them being sold publicly I just don't know.
I have a feeling Martin (member BundleOfKent) has actually seen one of these smurfs in real life. Maybe he might have a little more info.