If I remember correctly, exotics take the base price (~1000 GBP) and then there is an additional for the skin. Croc/Alligator was something like another 1000 GBP. I'm pretty sure Luk would know better though.
^In no way am I insinuating otherwise. There may be going on there, but from what I know, that's a special price. My decos on order were about the same price as those listed at Bespoke England, which is ~1000 GBP.