Sorry if this posts twice - am having trouble with photo uploads

Hi all. I have just gone back to my first love, paperweights and started buying some again, after buying vases for a long time.
I buy what I like, however am stumped to understand the huge variation in prices between different companies/designers. I show as an example two I bought recently. Both good designers, Colin Terris - Caithness, and Ronald Stennett-Willson, Wedgwood. Both about the same age, around 1974, both in good condition, and both with makers mark.
Why then does the Caithness one cost so much more than the Wedgwood one? I am hard pressed to find a reason? I think they are both gorgeous - that is why they are now mine :D - but can anyone explain to a novice why the disparity in price? The Caithness one cost me about 10 times the price of the Wedgwood one. Is it technically much more difficult to make perhaps - or is it just fashion?
I wait to be educated........... hopefully

regards
Jackie, West Oz.