Roger James Hamilton is a multimillionaire, the founder of the Entrepreneurs Institute, and the owner of Vision Villas, a resort for entrepreneurs in Bali. 

But at 18, he was a broke architecture student who didn't have the $800 that he needed to join his friends on a trip to Greece.

In his book, "The Millionaire Master Plan," he explains how he raised the money over the course of a week.

Living in Cambridge, England, at the time, Hamilton spent a few days sketching the popular tourist sites of the city.

He then had them copied on good paper, and sat on a busy street selling them for $6 each. While he waited, he drew more original sketches.

By the end of the first day, he had earned $230.

One day, an American tourist asked him to buy the drawing that he was working on. Hamilton refused, since it was his original and he still needed to make copies.

"Everything has a price," the tourist told him. "How much?"

Hamilton asked for $200, enough to take the rest of the day off.

The tourist handed the cash over, and Hamilton kept on working, ultimately doubling his earnings for the day.

That experience taught him a lesson that he's remembered ever since:

Wealth = Value  Leverage

The money that Hamilton earned came from both the value of his prints and his ability to leverage it.

"When people bought my prints for $6, it meant they valued my prints equal to or more than the price I set," he explains. "By making copies of my drawings, I was leveraging the value so I could sell the same picture twice or a hundred times with the same effort to draw it but a much bigger potential payoff."

In turn, the leverage raised the value of his work.

"When the tourist bought my unfinished original, he saw greater value in my hour's work than my leverage was rewarding me for a day's work. But he may not have paid so much if I was not selling so many of my prints."

Hamilton's $6 prints didn't make him rich. But they did get him to Greece.

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