Spay costs and procedures

What are the reasonable procedures a vet should perform when getting a JRT spayed? In anticipation of getting our puppy spayed in a few months (she's currently 5 months old) the vet printed out a sheet of all the things that will and might be performed. Not being made of money, I want to do what's necessary without paying for things that aren't essential. It seems like vets can always run this test, and that test, etc. I wonder sometimes if they play on our fears on insuring the safety of our pets.