Recently there was long thread about the BCA. I can now post possible answers to some of the questions, such as "Why is the BCA still raising membership prices when there is a significant amount still left in its coffers?"
I think these wellies are the same as those I spotted in a shop in Bakewell recently. The sole looks good but the uppers seemed very flimsy and probably wouldn't last long if used for caving.
These look more or less the same as "Muddies" wellies; neoprene construction. I use Muddies as my main dog-walking boots and they're as tough as, well, old boots. I've done many hard miles in my pair & I've always thought they'd be ideal for caving use.