It's time to consider the unusual gifts for unusual folks. There's nothing like showing you "get" your paranormal friend or family member more than the unique thing they may not have and really really want.
Let's investigate the wish list of those curious about our natural (and unnatural) world.
I do investigations of all arenas, and these IR binoculars (below) are my favorite thing! They are great for ghost investigations, UFO monitoring, and Bigfoot tracking. Good also for hunters and hikers/campers.
(can do photos and videos)
The most successful mic for capturing EVPs - omnidirectional.
and, no matter what kind of researcher you are, you need a camping chair -