I live about 1/2 an hour from the Caithness factory shop in Perth, Scotland. In the shop they have all the standard range of glass, most of which, are actually all seconds. There is nothing really wrong with them but they have all the perfect bits for sale at a premium. There are also some very expensive limited pieces for sale. Some of these are absolutely stunning and way beyond what they normally sell.
Most of the Caithness glass at boot sales and on Ebay is from the seventies and eighties when they were more succesful than they are now. Now owned by Edinburgh Crystal, themselves far from profitable, things don't seem to have changed much. The factory shop is full of display only pieces. If it was me they would be on display and on sale!
I am not a great fan of paperweights. Caithness are obviously well known for them and I have to say the display of paperweights contains some stunning pieces of glass.