I had a cat neutered less than a year ago and I didn't pay that much. My vet is in Stillwater. He is pretty reasonable. I also know of another vet in South St Paul that I hear is really reasonable as well.
Or maybe you could call Caring for Cats in No. St Paul. It's a feline rescue - they could have info for other places around the state.
PM if you need any phone numbers....
Meg