From the late 50's to the early/mid 70's there were a slug of these preset lenses on the market. For a while, throughout the 80's and 90's you could pick them up for a song at photo flea markets. Now for some odd reason they seem to have mostly dried up. A few, like the Vivitar 85mm f1.8 sometimes go for higher prices than a camera makers lens of the same focal length. Go figure.