Robin_Usagani
TPF Noob!
f/1.2 bitches! 
and that will create a 1.4x telephoto converter effect. So it'll be an 81.2mm effective focal length on full-frame EOS. And the edges of the frame will undoubtedly look like utter rubbish from wide-open down to about f/4.8 or so.
Probably close to $200. The only reason im considering it is because i got the lens for free. They are selling for $400+ on ebay.