You don’t need expensive comms to make use of the Unity Tactical MARK Kit helmet adapters. They shared a photo with the Peltor RangeGuard hearing protection mounted via their adapters. They will also work with the nearly ubiquitous Howard Leight Impact Sport headsets.
Night vision still isn’t cheap but it is more affordable and more accessible than ever. This could represent a gear item that you could save some money on while building your own night vision set up.