I’m an older psychologist. I no longer do testing. To keep current with the equipment can cost $8-10,000. When I worked In psychiatric hospitals, I had my choice of what test to pull. I was doing at least one full evaluation a week. Easily, 20 hours. Plus, I wrote my MS thesis on tests. Two of my advisers are famous in the field. People can do a full year post-doc in speciality areas, like the NS program at Yale. In my locale, I have gotten to know who is good at what. I try to recommend accordingly. The psychologists that I know who,do testing almost do this exclusively. I think nothing of recommending someone in a city 1 1/2 hours away.
Just wanted to add another perspective.