What they really mean is they are technology-based investigators, using a variety of technology to record, analyze and identify a haunting. Technology-based investigators differ from others who use psychics, mediums or sensitives as a source of validation.
High-end equipment can be quite expensive. Some equipment, like the thermoimaging camera, can cost thousands of dollars.
Why is so much money spent on this equipment? It allows investigators to find the truth and validate the existence of life beyond what we know and also for personal satisfaction. There is nothing more gratifying than collecting a genuine piece of solid evidence to validate the existence of the paranormal.
Collecting evidence is a source of pride in the paranormal community. It certainly is for us. We want to find meaning and justification for all the weekends spent away from family and friends.