It could be that the seller does not know that the signature is a forgery. The first time that I saw the vase was on another Murano board. It had been brought to an auction house to be sold. Fortunately, the auctioneer was a good one who verified the identity of things before putting them on the block. She wrote the Bianconi's, who told her that it was a forgery. I ran into another a couple of weeks ago on eBay and sent the link to the family. They wrote me back to say that they were not sure if the fake signature had been added when it was made or after. So many of the vases are out there that I suspect the signature was added close to the source.
The heirs are pretty firm about the fraudulent use of Fulvio Bianconi's name to sell glass (
www.fulviobianconi.com). The last one that I saw for sale on eBay went for a bit over $100 US. The winner was probably ecstatic to get a Bianconi for the small amount. I don't know how much the Polish vase would sell for -- probably not at all on eBay.
There are so many Murano fakes out there, it is hard to know how to warn people. There are a couple of excellent articles that people can pull up on eBay (the ones to the left of the search page). I wish we could get all of the oriental and south American pieces out of the Italian category. But I know that is not going to happen.
Anita