Sunk Cost

Once upon a time, I learned this concept of sunk cost which supposedly shouldn't be something that influence your decision.  This is hard for me to grasp still.

I have all my in use gears in Nikon I would be hard pressed to switch to another brand.  Though in reality my go to camera and lenses are quite limited, 2 bodies and 2 lenses for 99% of my shoots.  The rest are just for fun pretty much.

After shooting with a motor drive for years I find it hard not to.  The balance without the grip is just not right.  The motor drive works just fine provided I don't need to hike up and down for a long time.  Except for the F5 I still don't own any camera with integrated grip.  Whenever I see a camera with integrated grip I am interested.  I instantly recognize it as a high quality build camera.  So naturally I am fascinated by the Olympus flagship whatever OM-D blah blah is and the soon to be released rumored Fuji for the 2020 Olympics.