Lucy Guo, 30, saw her net worth reach $1.3 billion in April. But the entrepreneur, who is now the world's youngest female billionaire, is committed to finding the best deals — even if she can afford to pay full price.

Guo told CNBC on Wednesday that she remains "frugal," admitting that she has done things like reserve flights at the airport and cancel them later so she could have a meal for free in the Amex lounge. She also rides UberX, the budget-friendly, low-cost version of Uber, and compares prices for food before buying something to eat. Her closet consists mainly of $10 pieces from stores like Shein.

"I'm frugal at some things, and I spend more on other things," Guo told CNBC.

Lucy Guo. Photo by Gonzalo Marroquin/Getty Images for Passes

Guo's fortune was built via Scale AI, the AI data labeling startup she co-founded with Alexandr Wang in 2016. Meta made a $14.3 billion investment in Scale AI in June, acquiring 49% of the startup and allowing the company to achieve a

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