This seems like a terrible idea for someone with MS. Once/if his disease progresses, he won't be able to get to or from his own home. I didn't see ramps.
It's impressive that he managed to do it himself, but it doesn't seem like he's being honest with himself about his condition. I'll hope he gets a chance to enjoy it before he can't.

The price doesn't seem bad for a dream home.

Seems more like an investment thing than a permanent residence.

On the plus side, once he passes away they can just brick it up for instant tomb...

France has many troglodytes like this one living in the Loire Valley. Just google "Loire Troglodytes" to see the pictures.

In a hole in the ground there lived a hobbit. Not a nasty, dirty, wet hole, filled with the ends of worms and an oozy smell, nor yet a dry, bare, sandy hole with nothing in it to sit down on or to eat: it was a hobbit-hole, and that means comfort.

I was kinda hoping for devolved humanoids with half blind greyish eyes sniffing, barking in the dank caverns, and murdering each other in proximity to you as you flee, crawling on your hand and knees with its nails still freshly embedded in your flesh.

Nah, that's Cannes after the film festival.