Suggested retail is generally $500-$600, I believe, at least in Ruger catalogs. I paid $425 for mine, which has the same physical attributes as you described.
Just the other day at Walmart, they had a couple of Mini 14's. They have them there almost every time I go in and they are generally around $425.00 for what you describe. You could pick up mags at a gun show or online for relatively cheap.