Spam Websites or Not. Wrong System.Why is that?

I don't understand the system those websites work. If your website is not a spam and is a truly trustful website then why do you charge $50 or $90 for registration? And you promise $3,000 to $10,000 a month. When people need jobs means they have no money. I believe the safest method and the trusted method those companies could ever do is FREE registration, Pay your member the promising $3,000 a month and then charge from it, the $90 you want. But no one does that as far I know. Is there?

Legitimate businesses with real jobs, don't charge for information about the job. If a web site wants you to pay up front, they aren't trying to hire you, they're trying to get your money.