Like Knabe I like to use the dehorning paste. If you'll just rub where the horn buttons are, you'll get good at detecting if they are horned. Cut the hair down and apply dehorning paste about the size of a nickel to the button and the horns are gone and the calves will look smooth polled. Should seperarte the calf from the cow for a short time period to keep the cow from licking the paste off.
$45 for a vet surgical dehorn? That's the cheapest that I've heard of.
John Earnst from Iowa does a good job for under $50, but John's no vet. Just a darn good cowboy!!