Sounds to me like the BF is rational thinking individual and would be up for it.

They have invested a tremendous amount of money in you and you are repaying them by taking what they are paying you and not working for them during the time that you are focused on something else.Trying to rationalize it is useless. 

There's a lot of desperation and rationalizing out there; and also a lot of one-time flippers.Note as well, that if you zero out the financing costs, per Tim Gordon above, and pay 80% of the ARV for Costa Mesa, you are lucky to come out even.

So be careful to not let emotion enter your brain and stick with rational thought, evaluation and numbers.

Even though, as @Wayne Igo pointed out, the rational decision would be to gamble for the $100 million, we humans are not entirely rational creatures.

He does have an emotional attachment to the property, so hopefully he can look at the numbers in a rational way.

You are rational about what your property is worth and you understand the challenges.

Here's how you need to think about this:Current cash flows put this at 7.5 CAP - this may be very inaccurate since your are using 50% expense ration to arrive at the NOI, which is likely a load of BS.

(The property as is is below its market value in rents, but I would still be updating the properties to rationalize an increase in rent.)

He had a friend of his there to also speak with me and, although she was obviously on his side, she was actually a rational individual who understood the situation and in essence acted like a mediator.