I'm shooting an N80 and am looking for a tele-zoom that I can put a 2x on occasionally. My needs are for something that can get me out to 400mm with or without the multiplier and which has decent optics. Extreme focal length ends do not have to be all that great but I need something that will give me good resolution in the 200 to 400 range. 3rd party lenses would be ok. My price range is aound $650, with a used lens probably being the best buy.