If by 'worth' you are asking what they would cost to buy or you would get for a sale, it is possible to get a general feel for a price. There are thousands of Caithness designs (well, way in excess of 1,000), and some unlimited editions ran into 1000s, so there are quite a few Caithness weights about. As a general rule the 'swirls and bubbles' type sell for well below issue price (20% or so), and somewhat more attractive ones (IMO) for 20% to 40% - but there are exceptions, for some weights that collectors really like (and I don't know exactly which these are, but if you have a Shipwreck....).
Stardust was issued at £20: I would be delighted of I had one and got £10 for it. Henry VIII was issued at £50, as was Elizabeth 1, but the mixed news is that the planned edition of 250 each was badly undersubscribed - only 50 or 60 were sold. So, they are not common - but on the other hand, they were not seen as very desirable! If they are like modern Baccarat sulphides in respect of depreciation, then £10 - £15 each sounds par for the course: but sulphides are not my area of expertise, I'm afraid.