Kari, which type of "fish paperweight" are you referring to? A link or photo would be useful.
A Google search shows various possible items, most being the larger "aquarium blocks" which are not really paperweights. Some people seem to say things along the lines of "Licata for Cenedese or A.V.E.M." and perhaps that indicates a general uncertainty about attributions.
I suppose that an Aquarium Block, or a Fish embedded in Bowl or Plate, that might have been designed for a glassworks by the artist Riccardo Licato would be of good quality. That could be a good reason for a higher price when compared to a similar item but not designed by Licatao.
An interesting link is
this one in the Antique Helper site showing an "abstract decorated aquarium block" with realised sale price of $17,000. I guess that none of the more usual "aquarium block" pieces, even with neat filigrana-type fish and fine multi-coloured strands of seaweed, would reach anything like that sort of price.
By the way, beyond my Googling, I know nothing at all about Licata and his connection with any glassworks and it is just supposition on my part that the Riccardo Licata linked with Cenedese (or any other glassworks) is the same as the artist Licata!