Ed:
We have the cheapest model Cabela's had with remote control; it was about $150. IIRC range is listed as 300 yards, there are 7 levels of shock setting plus a "reminder" setting that just plays the buzzer tone that accompanies the shock. I like that reminder setting; after training it's just as effective.
We got it about 4 years ago and it probably saved the life of our half-Lab/half-Coon Hound cross (if she didn't start coming when called, my wife was going to kill her). The system is now on it's second dog, having gotten much less use (so far) on our Cardigan Welsh Corgi. The interesting thing is when we tone the Cardigan, the Lab hears the tone and beats her back to us! GOOOD doggie!