Gravitar Pal

I got a hankering the other night to play some Gravitar after stumbling across an advert for the original arcade machine, Being in the u.k i would obviously require a pal copy, I hopped over to ebay thinking i would pick one up for cheap only to discover there wasn't a single copy for sale a brief scan around also turned up nothing, Is this a rare title in the u.k as it certainly isn't stateside.

I have one good contact for carts that has one copy for sale but he wants £20.00 for it and i don't wish to play it that much