I don't think it is Alessandro Mandruzzato, because his vases have a square inner opening to the mouth. However, it might be his father Luigi Mandruzzato. The father had the circular opening in at least some of his vases. Campanella, Bucella, V Nason, and others made similar vases. I hoped someone would recognize the blue casing glass to narrow down the list of possibilities.
I am a definite show-me person. I rarely trust attributions unless someone can show me a label, a signature, or documentation --that is unless the person doing the attributing is an expert. I particularly don't trust attributions if a vessel is a common form, such as the one in this thread. Someone would have to convince me it was Poli before I would consider a Poli price.
There are certain names, e.g. Poli and Martens, that are put on eBay so much that I've learned to totally ignore them. The object is to increase the price of the piece to people who don't know any different. A merchant or seller owes it to their customers to do the research and not to attribute because something looks like it might be designed by someone. IMO, if a piece cannot be documented, then it should simply be sold as Murano glass and let the buyer use their own imagination.