Heh, good luck, I had trouble convincing him to sell them at all, even after I offered the full asking price and offered to arrange my own courier.
I ended up getting a pair new from the US, cost me £450 all in, brand new with brackets, bulbs and all. I'd do that, then sell the one you have, perhaps?
I have one to sell, but I'm sure it's driver's side. Everyone seems to be after a passenger side one like I was!