About 60 quid, though I bought them from an auction site in Japan (where I live). It's easy to find XXL sizes for gloves, jackets etc. on the auction sites over here due to size mistakes.
I saw them advertised online for $269.99 which is about 130 quid, so I guess I got them half-price...sweet

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Spidi's an Italian company by the way, so they probably have tons of resellers in the UK.
I also have a year-old pair of their winter/waterproof A83 SportComposite H2OUT gloves. They saw me through a freezing winter with excellent water-proofing; hard-wearing too. Same knuckle protectors as the Penta. Pic:
