If the money he is losing is meaningless to him, why has he launched lawsuits to back out of the purchase and sue media watchdog orgs? Why did he replace himself as CEO with an advertising exec? Seems like the money is pretty meaningful to him.
It's really just an extreme version of a boat. They seem like fun, but they're money pits, and a lot of work goes into keeping them running. Alternatively, it's the Cartmanland scenario.
I imagine you're right that the lost cash does have meaning to him, but it doesn't appear to be the primary motivator for his decisions (and is definitely not driving his near-term decision making).
Primary motivator being insecurity and rapidly deteriorating mental health