But the cost difference comes down with a $3500 Canon 5D with 50mp, or a $3000 Nikon D810 with 36mp, or a $3200 Sony A7RII with 42 MP.
Following the idea that the "best" camera is the one you have with you. A simple 2x or 4x stitch with these cameras with a decent lens can get you a pretty damn good file. As I am often on the road for commercial work and only have room for a DSLR kit and lighting gear, suitcase, ladders etc. sometimes I run across a personal image that can't wait. I have gotten very good at even hand holding the DSLR in good strong light for stitching purposes.

FWIW I recently dumped my Canon bodies for the Sony A7r (with which I can still use my Canon lenses). A7r camera bodies are like $1400.00 right now. Canon has fallen behind in the most important tech-dynamic range and I got tired of waiting for them to catch up with Sony and Nikon.