Hi and welcome.

Unfortunately, we do not really tend to discuss values here because they are very subjective in the secondary market.
We're really about the much more exciting business of identifying and discussing the glass.
However, there is a lot of interest in the Hadeland glassworks in Norway itself, and Gro Bergslein's work is desirable.
If you were to put it up on that well-known auction site and
ensured the auction was advertised in Norway, I'm sure it would happily make its own price.