Its only expensive because people will and do pay silly money for it because real carbon also aint cheap. Supply & demand etc.
Considering a light weight dry carbon 2x2 weave (300g sqm for example) is about £30+vat (per sqm) and a similar prepreg (LTM26 for example) is about £90+vat per sqm, having things hydro dipped isn't as expensive as it "could" be lol
Altho IMO its complete an utter tat but meh
£450 to have your trims dipped? Jesus you could have them wrapped in real carbon for the same money, or get a used set off ebay for a tad more. When I get round to it ill be doing all my S Line trims in carbon when I have a spare weekend lol