I ran into a seller at an antique fair this past weekend with a nice one for sale. It seemed to have some sort of hazing or filming on the rear element so I presume that was the effect of aging spoken of here. The seller was asking $450 U.S. for it. Not knowing anything about it at the time, I thought it was a bit much for a lens sans shutter, even one that fast. He mentioned the radioactivity as well.