This is just for clarification: this lens is from an older type Xray machine and was used as a relay lens to project a very faint (hence the f1.0 speed - I have some which go down to f0.75) image to a recording camera. These lenses do not need an iris nor focus mount and have an extremely shallow DOF due to their speed. The biggest downside is the very short back focal length which does only allow a few inches of distance to an object to shoot when mounted to a modern DSLR (which I did with several of mine). The images are very soft and dreamy, quite nice effect - but forget about taking portraits or anything further away then a few inches. I bought mine in a surplus store, so I will refrain from commenting on the asked price.
And btw just to be precise: this is NOT A NIKON lens as labeled, it is FOR NIKON, but FJW industries (many other company made such lenses, like KOWA, ZEISS, LEITZ, RODENSTOCK etc.)
Nice shots shown!!