Wollensak's numbering system for Vitax lenses changed at some point, so an earlier Vitax #3 was a 16" lens and the later Vitax #3 was a 10" lens. The 16" lens is probably worth a bit more. I'd say the deal he's offering you is very fair because you could pay that much for the lens alone. I love the Vitax lenses and the 16" makes a fine portrait lens.