Maybe 2 is a micro-HDMI with a couple pins missing 
Nope, it's a so-called UC-E6 cable, used mostly on Japanese cameras (my Nikon reflex, e.g. - that's why I recognized it...).
Not at all unobtanium, but not cheap.
Not exactly. UC-E6 is the part number for Nikon’s
cable using that plug, not the connector itself, which is commonly referred to as the “8 pin mini-B” connector. (I also object to using Nikon’s part number to refer to the style, since many other digital cameras used that same connector. IIRC it predates the official mini and micro USB connectors.)
Using the generic term gets far more results.
I haven’t had any luck in finding out who actually makes the connector, though! Anyone got a list of Japanese connector manufacturers?