Lots of good scopes in that range.
If you're looking for something like 3-9X40 or 2.5-10X40, for $300 -$400 you can get a Bushnell Elite, Leupold VX-2 or a VX-3 2.5-8X36, Meopta, Minox, Nikon Monarch, Vortex Viper, Weaver Grand Slam, or Zeiss Conquest.