Fujifilm GFX mount
Fujifilm's 44x33mm medium format, and the system that made the format cost less than a full-frame flagship. The GF lens pool is small on purpose and almost entirely weather sealed — the two tilt-shifts are the only exceptions. Note that the GFX100RF is a fixed-lens compact and does not take these lenses, and that the 50MP line ended with the 50S II.
9 bodies and 25 lenses tracked. Lowest used prices pulled daily from the major used-gear sites.