A simple form letter would be fine. Advertised salary ranges can be misleading. Explain during an interview how the salary will be determined and explain what weight will be given to years of experience, qualifications, and education. Although I have over ten years of experience in libraries, for one position, I was offered a salary near the bottom of the advertised range. Explain the benefits clearly.
Benefits can certainly make a big difference to the applicant.
Vacation, educational, insurance and retirement benefits can vary dramatically from library to library. The cost of insurance for a person needing a family plan can be a serious issue for the potential employee. In some situations, a good benefit package can go a long way towards making up for a lower salary. The opportunity for growth should be a part of any library's plan. Even a small library should be open to new ideas and technology changes.