I believe I read about a month or so ago that Bezos plans on selling ~$1 billion worth of stock annually to fund BO, I could be misremembering the exact figures though. Even at that burn rate, assuming Amazon continues to do well, I don't think it will be too much of a drain on his wealth. Plus, he seems like a pretty long term thinker so I don't think he'll throw in the towel even in FH captures a big chunk of heavy lift. BO is currently investing around $200 million in a new production facility in Huntsville. I'd say it's more likely that Boeing/LockMart try to rid themselves of ULA than ULA acquiring BO.
Bezos started BO around the same time as SpaceX, and has spent just as much money if not more, and accomplished next to nothing. He will need to pour many additional billions in to even make a race of it, the way the BO turtle moves.
Maybe he's hired the rocket guys who can't take SpaceX's speed and like to actually spend evenings at home with their family :)? Only half kidding here.
Or maybe Bezos didn’t understand orbital mechanics and picked the wrong approach: They went into space and landed again, but they did not go into orbit yet (as far as I know) and landed again. De-orbiting and landing is different from just going straight up and returning to the launch site that is below your feet.
Well, at a net worth of approximately 90 billion and assuming a 5% return rate, he can sped 4.5 billion dollars every year forever on the blue origin and never lose a penny.