Cheap, fast standard prime lenses for the Nex 6?

The first question is do you want AF?  If so the rest of this statement is moot.  I use mostly MF on the 7 and with focus peaking and practice have come to prefer it.  I always know what I have focused on, can follow a moving target with the focus ring, and have instant shutter release when I press the shutter.

I prefer the 35mm length (52.5 ff equivalent) as a standard lens, and have tested many, including some Zeiss and Voigtlander.  The best I have found is the Canon FDn 35 f2.  There is the older FD which has a thorium element, and it is almost as good.  These have outperformed anything I have put on the camera, although I have not gotten into Leica prices.  Be forewarned, however, the thorium versions are heavy, but not really unwieldy.  All of these can be purchased for under $300, the FD's for under $200.  As predecessors to L glass they are sturdy.

Finally one caveat:  The IQ on any older glass can vary a lot between identical lenses.  The first FDn I had was inferior to my thoriums, but the second outperformed them all.

Michael