A 2-day weekend enrichment seminar I attended cost $12,500. One of the millionaires there said he learned some tricks that, when applied to his current business, generated $10 million! So is spending $12,500 to increase income to $10 million, worth it? Of course it does.
I know poor people can't start by attending events with such large expenses. But they can read $20 books that are worth $20,000 if they apply what they learn from it.
The rich invest their knowledge by paying those who have achieved success. When I started investing in real estate, I bought a $25 book that gave me the knowledge and courage to get started. Next time I bought a ticket to the trade show for $200. With the knowledge gained from it and practical application, I made nearly $100,000 the next year. Then I invested in a year-long program that cost $4,000, and made $200,000 the next year. (I'm not going into detail because I just want to emphasize that the more you invest in knowledge, the more money you'll make.) Wisdom comes from the application of knowledge.