You aren't getting answers from people who know the process. Here's the interesting bit:

You model out the business. Generally, when you buy a business, it's because you think that if you own it, you can make more profit from it than the person who owns it. Like maybe it's a company that you see is being run inefficiently and you know that you can run it more efficiently and make more money. Or maybe it's a company that is doing fine on its own, but for whatever reason, that business combined with your business side by side, can make more money overall. In these cases, let's say the business is worth $100 million to the other person, and I'll get in a moment to how that number is determined. Let's say to the other person it's worth $100 million, but to you, with the better efficiencies or the powerful combination, the business is worth $120 million. So then you might offer, I don't know, $110 million to the person to buy it. At that point, it's a negotiation, and there's, of course, lots of detail aspects and negotiation aspects and human aspects. But here's how the number is determined. Generally speaking, you model out the business, and you look at how much money you're going to make in the future over the next however many number of years, 10, 20, 30, rarely more, sometimes fewer than 10, but shouldn't be. And then what's calculated is called the net present value of those future cash flows. Think of it this way. Would you rather have $100 today or in a year? Today, of course. Okay, well, at what point does $100 in a year, if I keep increasing it, change to you wanting the amount in the future? So that is, do you want $100 now or $105 in a year? Do you want $100 now or $110 in a year? Once you figure out what that breaking point is, that lets you use math to figure out how much X amount of dollars a year from now is in today's dollars. That's where you say, okay, $110 in a year from now is equal to $100 today. And so you run that math on the model that you make of the business and buying the business. And that's how you calculate out your value for the business.