Good basic lens for Nikon n75?

I don't know whether I should buy the body on its own, and a lens separate or just buy it for $100 with the 28-70mm kit lens it generally comes with. The body itself runs about $40 used from what I've seen, so if any of you have suggestions for a lens under $75 or so that's compatible it'd be appreciated! I already have a portrait lens for it, I just need something that'll be good for if I'm out and about and wanna take a quick shot.

Added (1). I should also add I don't care if it's manual focus or anything, as long as there's no vingetting. I guess that goes without saying though given my price range.

The 28-70's a good start. You do realise that this is a film camera and that 50mm is a standard lens (not portrait) ?