$500 for a fixed scope? For that amount of money, you can get a VERY GOOD VARIABLE SCOPE! Zeiss Conquest, Nikon Monarchs, Elite 4200s, even Leupold VX-IIIs.
Still, if your heart is content on a fixed scope AT OR CLOSE TO THAT PRICE RANGE, then it would be hard to beat a Leupold FXIII.
Zachary