Hello all, I saw a Bushmaster w/ a short Hogue stock, 16" barrel, 1 30rd mag, w/ carry handle, used for $600. Is this a good deal? This is a used rifle, so don't know how many rounds went thru it. I new to the "AR15" scene, so don't really know what to look for, (i.e.) stocks, barrel, etc. Your insight is greatly appreciated.