IDK here in Denmark it's kr149.995,- DKK including 25% VAT.
That's only £17.154,- GBP, so more than £3000,- cheaper!
https://www.bydauto.dk/modeller/byd-dolphin-surf
Dolphin Surf is the European version of Seagull.
Despite the link you post has it starting at £18.650,- GBP, that's still more expensive than in EU apparently.
Maybe it's more expensive because instead of having the steering wheel to drive in the right side, UK has it to drive in the wrong side?