Don't pay £325 for one of those!! Barely worth £100 I'd say, most of them aren’t even Fair.
£150 for one of the better ones I'd say. For £325 you'd want one in NF condition. They really aren’t that rare in low grades as you can see from that dealer's pictures.
This page at London Coins will give you a more realistic picture hopefully.
https://www.londoncoins.co.uk/?page=Pastresults&searchterm=Halfcrown+1905&category=9&searchtype=1
One i bought NOT attributed off a dealers website ,he is a good friend ,so did tell him what it was but happy to sell it me 👍
They are easier to spot with the other indicators ,die crack to the left of DEI and a wider I in Gratia.
Dont see many in a decent grade 1848 /6.