Masters vs the DNP

I am 50 years old . I will probably work for 15 more years?? I have my MSN and I am certified in emergency nursing. I am a part time staff nurse. I am chair of the research comittee at our hospital. I also teach BLS and de esclation. I am looking to leave the bedside of nursing and go back to school. I am looking at a Post masters certificate which will educate you 1-2 years and prepare you to take the Certified Nurse Educator certification. Or, I can go back for 3 years PT and obtain my DNP with a primary in education and a secondary track in research. I enjoy education and I enjoy research and would to work with nurses and bring both education and research to them. Which was should I go??? I is worth the DNP ?? I mean to spend 30 thousand .