In case you're interested, I recently bough a box of grey filters from here:
Had no problem with the transaction. Shipping costs are reasonable, not cheap considering the small item but far from obscene. It took slightly over a week to ship from Poland to Germany, IIRC.
I'm kinda surprised now that the description says "(pair)". I had a look at my order confirmation and it says "pair" as well, so I must have overlooked it the first time. Anyway, I received 8 filters in the sealed original packaging complete with box and fitting tool.
I may be willing to sell two of my fitlers but have no idea if that makes any sense at all as I have neither a spare box to send them in, nor a spare fitting tool.