How the 'Garage Sale Millionaire' flipped a $12 tin toy for nearly $1,000

Aaron LaPedis has made a fortune finding interesting stuff and reselling it on eBay, Craigslist, or directly to individuals.

He's been honing the skill since he was 10 years old, when he hosted his first garage sale.

Since, he's reached the seven-figure mark and written a best-seller, "The Garage Sale Millionaire," which offers up tips on how to track down hidden gems and make money off of them.

He's also made nearly a grand off a $12 tin toy, he explains to Farnoosh Torabi on an episode of her "So Money" podcast.

While it wasn't his most lucrative find, the 1932 tin toy from Germany was "one of my favorite finds," he says. "I picked it up for $12 or $13, and within about a week, I flipped it on eBay for almost $1,000. ... This one happened to have a monkey on a motorcycle, and he was clapping his hands while the motorcycle was moving forward."

This thousand-dollar find wasn't all luck. To find the hidden gems, you have to first know exactly what you have ... and what it's worth. "Every day, people mis-list what they have, because they're such in a rush to put stuff on eBay," LaPedis explains. "They don't take their time. If you don't know what you have, don't sell it until you do."

You also have to become an expert in something you really like, he emphasizes. For him, this means coins and historic memorabilia.

His expertise in historic memorabilia made this particular flip easy. "Tin toys were really popular back in the early 1900s," he explains. "A lot of them - because of World War One and World War Two - got brought over from Europe to the United States, and a lot of them are really intricate. They're windable, they're made out of thin tin, and they do amazing things. ... They can go anywhere from $5 to several thousands of dollars, depending on how rare they are. I'd seen this tin toy before and it was an easy flip for me."

At the end of the day, anyone can find treasures, "but the way you do that is by becoming an expert in what you love," LaPedis says.