I agree that this is a game for Mayweather. I think this is a charity fight and not a title fight. If you are going to ask me then everybody would be placing their bets at Mayweather and that this match is not really a match worth betting for. If you are going to bet for Paul, then your bet is already a high percentage of losing. So I am not sure how this fight will go but the bet would not who will win, but rather what round Mayweather will be able to knock out Paul.
The idea of this fight is not to earn on bets, but to earn on selling PPV subscriptions and commercial. Betting in this fight is just like an addition.
For example for the freak fight between Ben Askren and Jake Paul 1.5 million PPV subscriptions were sold. Its price was around 50 to 90 bucks (depends on how soon before the fight you buy it). 1.5 million PPV is the same amount UFC even Mayweather vs Poirier 2 event get. In the word of money, freak fight generated same interest (but more profit, as UFC PPV cost less) but more profit. Imagine how much Mayweather vs Paul profit would bring to promotors and TMT organization.