Values for any paperweight will be determined by supply and demand.
If you're intending to keep this item and want to insure it then a replacement value will be required. Probably best obtained from a dealer or by comparisons with dealers website prices. If the item is stolen or damaged then it might be difficult obtaining a 'equivalent' replacement so this value may be very much higher than the market value or sale value of the item.
If your thinking of selling, then check ebay and other 'market type' sites which will give you an indication.
The thing to bear in mind is whilst there might be general price ranges for certain types or designs of paperweight, if an item is unusual and/or rare then you can tear up the rule book (is the world record still $269,000??).
On that basis I would suggest that your piece is valued at not more than $269,000!!!!!!!!!!!!!!!!