Do all things get cheaper by the dozen _ even children? Things are starting out that way for Vicki and Stephen Kesler. Valley View Hospital, where Mrs. Kesler had delivered six of her most recent children, provided its services free when she went there for her 12th. The child, Breanne Marie, was born in July. ``I thought it would be nice to do something for them because they had supported us so much over the years by having their children here,'' said John Johnson, the hospital administrator. Betty Mahan, a hospital spokeswoman, said Saturday she did not know how much the free services were worth. The couple have lived in Rifle, in western Colorado, for 10 years. He is an engineer and she is a homemaker. Mrs. Kesler said that anytime she has to fill out a form that asks about her employment, she writes, ``The Kesler home, as mother of 12. That should be sufficient.'' The children range to age 19.