FYI: You can do Casino Heist prep in invite only sessions.\n\n I just did all prep work missions and got griefed 4 times and failed 2 times. I hate life. I spent 6 hours alone..

You will earn different amounts of money depending on the primary or secondary loot you grab. There's also the question of how many players you choose to use for the heist, with Cayo Perico being the first you can complete solo.