Please see Bushnell Exursion 20-60x80 with ED glass at price 384 usd at Opticplanet.com also. Price is higher than your target but glass is pretty good.
You want a Konuspot 80. 90-95% the scope the Kowas are at about $200. I did a LOT of hands on research with this, and was fully willing to spend for the Kowa.
Jim Owens has a good description of it here. Just hit it with a nice coat of Krylon Ultra Matte (I did black) and you're good to go!
given time and patience you can find insane deals on ebay. Last year I purchased an older but perfect condition Prominar spotter for $100. It has far better glass than my Nikon.