With so much doubt around Ohtani's pitching future, I will be amazed if anyone offers him anywhere near a half billion dollars. He has a dodgy UCL and is facing a very great possibility of a second TJ procedure, at just age 29. It would be a reckless gamble to offer any pitcher with that profile a long term deal, let alone a record breaking one.
I can see him signing a 2 year, 'prove you're still a pitcher', deal with the Angels.