To add a bit more to Alan's comments ...
The Caithness weight "Cascade Rainbow", was, according to the Charlton Catalogue, designed by Peter Holmes and the first issue had a "PH" cane, but from 1975 had a "CG" cane. It had an original price of £17.00 (with the PH cane) and £19.50 (from 1975), but the stated "value" in the catalogue (as at c2004) was £100. For what was essentially an unlimited issue, as opposed to a specialised limited one, £100 might seem rather a lot. But, as Alan has hinted, collector desirability counts more than most other factors.
In terms of technical issues, I guess the Caithness design would be more technically difficult than the Wedgwood one, but I agree with Alan that from a collector's viewpoint, that might not count for much unless the technical side of things is known to be really difficult.
Another point is that, as far as I can tell, in the collecting world, Caithness has always had a greater following than Wedgwood - the latter being often (although wrongly, in many people's minds) thought of as a producer of lower-level gift items as opposed to "better quality designed" items (at least, for the paperweights). In fact, I think it is possible that many people who have a Wedgwood paperweight will not have heard of Ronald Stennett-Willson and will not know of his importance in the general scheme of things. But more folk will have some knowledge of Colin Terris - even if he did not actually design many of the weights produced at Caithness Glass.