New or used? Pre/post ban? Blued or Stainless? What sort of features/accessories included?
I've seen prices range from $350 or so, up to $500 or even higher, especially for a pre-ban w/ factory folding stock and factory hi-cap magazine(s). You could probably count on roughly $1000 for a specimen of the latter type.
I have one I'm looking to sell for $500. Here are the specs:
Ruger Mini-14 pre-ban (183-prefix, bayonet lug and flash supressor), includes 7 aftermarket 30-round mags
The price I'm asking is roughly what I paid for it, minus some extras that came with it when I bought it that are not included. I don't know if that is a particularly "good" price for it, but I'm not terribly desperate to sell it, so thats what I'm asking for it.