You might look into a Bushnell Trophy. Like Mr. Ruger said, Swift would be another good choice in that price range.
You might also talk to the dealer that you bought the rifle from and see if he would get you a scope for cost, since you bought the rifle from him. I've done this for customers before, so it might be worth a shot. If he would, I look into a Nikon Buckmaster or Bushnell 3200. Both would be close to your price at cost.