eBay
This was part of my sons collection, we were given it by the Games Workshop when we bought a large 40k box set - we were told that only 2 were made per shop. It's been impossible for me to obtain guidance on price. Whilst the helmet itself is not damaged, some of the paintwork is. Apologies for changing starting bid but I took it to someone who knows more than me who has told me I should ask for more