The Doomsday Heist is one of the best-paying missions in the game, but it also requires significant investments. However, the total cost of this heist is hard to estimate. First, you’ll need to buy a facility that ranges from $1.25 million to nearly $3 million. Additionally, you’ll need to purchase equipment for $65,000 for the first act, $95,000 for the second act, and $120,000 for the third. However, some of the equipment can be stolen to save a lot of cash if you’re not opposed to theft.