Next time you're out pursuing a weekend garage sale, don't quickly turn a blind eye to knick-knacks and trinkets, because they could be worth a small fortune.  

If you watch enough Antiques Roadshow, you know that some of the strangest items can get the highest bids at auction.

From old baseball cards, to scripts, electronics and furniture you could come across a treasure at a local garage sale and not even know it!

Check out these amazing finds these lucky people had unexpectedly.

$25 Card Table Garage-Sale Bargain, Is Sold for $541,500

A card table that Claire Wiegand-Beckmann bought for only $25 at a garage sale proved to be a good investment. As it turns out the table was an 18th century rare find and sold for $541,500.

"I'm flying," 71 year-old Claire said after the sale.

The retired teacher had bought the table at a garage sale more than 30 years ago and had it in her home in Bergen County, New Jersey.

"I've always been a garage-sale enthusiast, but I never expected to get this much for anything," she said.

The table was purchased by Israel Sack Inc., a New York dealer of fine American antiques, which as it turned out, was only 1 of 6 made by the Boston furniture maker John Seymour & Son.

$25 Painting Sold for $79,500

Wanda Bell, an antique collector purchases a painting for only $25 at an auction near Nashville 8 years ago. She named it "Uncle George" after bringing it home.

Wanda was able to sell the painting to Connecticut antiques dealer, Wayne Pratt. The work of art was believed to be one of the best-preserved examples of New England artist Sheldon Peck's early work. Entitled "Portrait of a Dark-Haired, Blue-Eyed Gentleman", the painting dates back to about 1830.

"I am very sentimental and I will miss him," said Bell. "But I am delighted it is going to someone who will appreciate it."

$2.48 Declaration of Independence Copy Sold for $477,650

When Congress put William J. Stone up to the job of creating 200 copies of the Declaration of Independence in 1820, Michael Sparks from Tennessee never anticipated being in possession of one of them.  

It was believed that only 35 of those copies were in existence today until Michael found the 36th reproduction.

Shopping at a garage sale, he purchased salt and pepper shakes along with the document for $2.48. After examining what be believed to be a reprint copy, he noticed an engraving that was far too intricate for a mass-produced version. After his suspicions were verified, he sold the 36th copy in existence for $477,650.

Andy Warhol Sketch Purchased for $5 Valued at Over $2 Million

When British businessman, Andy Fields, purchased what he believed to be a child's drawing at a yard sale in 2010 in Las Vegas, he was surprised at what he later learned. He was correct to assume it was a child that drew the image, however he didn't know that it came from a future world-famous artist. Andy Warhol had sketched the drawing when he was around 10 years old while he was on bed rest, suffering from cholera.

The picture is of 1930's singer Rudy Vallee. The piece was appraised at roughly $2 million, however Fields is still the owner and is unsure if he would be willing to sell it or not.

$3 Ceramic Bowl, Sold for $2.2 Million

A family from New York purchased a white bowl for $3 at a garage sale in 2007. What they could have never imagined, however, was that this 5 1/2 inch piece of china could be worth millions.

6 years after buying it, the family had the bowl appraised and learned that it originated from China's Northern Song Dynasty. In 2013 it was put up for auction and sold to Giuseppe Eskenazi, a British art dealer for $2.2 million dollars.

Tudor Bed Frame Purchased for £2,200, now worth £20 Million

This beautifully carved four-post bed was left behind in a hotel parking lot in Chester, England when the building was being renovated. Ian Coulson purchased the bed for £2,200 in 2010. He then took it to TV historian Jonathan Foyle to confirm his suspicions. After DNA testing of the timber it was revealed that the bed in fact belonged to King Henry VII, back in 1468. The bed's estimated worth is said to be over  £20 Million.

$5 Stock Certificate Valued at $130 Million

When a California man purchased a stock certificate for a company called Palmer Oil Co., he would have never believed that it would turn out to be for the predecessor company Coca-Cola.

After Tony Marohn bought an antique stock certificate in 2008 for $5, he spent the final year of his life battling the beverage company to claim his money. Though Marohn died in 2010, his family has continued to the legal battle to get the 1.8 million shares of the soft drink maker.

Think you could get your hands on a valuable find? Try these tips for your own garage sale hunt.

For some people, there is nothing more exciting than driving around the neighborhood on the weekend in search of some great garage sales. But what is the secret to scoring something amazing?

Try these great tricks the next time you are out looking for a garage sale.

The Early Bird Gets the Worm

One of the best times to visit a garage sale is in the early morning, just as the sale is getting started. Big ticket items will likely be sold in the first few hours, so get out there early!

Don't be afraid to head out if you're a late riser, though. As the day wears on sellers are more likely to reduce their prices because no one wants to pack up a bunch of unsold items and put them back into storage.

Do Your Research

A savvy garage sale hunter, knows how to get the best bang for their buck. Whether they're looking for products that they can turn a profit on, by reselling them on eBay or Craigslist later, or by having to avoid going out to pay full price for an item you already need.

It's best to avoid items like electronics and other big ticket items if you're not familiar with them or haven't done your research beforehand.

Become an expert in something, whether it's old records, coins, collectible or antique furniture, once you know a lot about the subject the better chance you will have about being able to spot a treasure.

Learn to Negotiate

If you hate to haggle, there are some simple tactics you can use to avoid making it an unpleasant experience, but still scoring a better price than what the seller is asking.

• Form a relationship with the seller by striking up a conversation. Ask relevant questions about the pieces you're interested in and just form a friendly relationship to make it easier to acquiring a deal.
• Don't show up to a garage sale wearing you best clothes and shoes. If a seller feels like you should be able to afford more than you're asking to pay, it's unlikely you'll be able to score that deal.
• Bring small bills so you won't have to ask for change after you've haggled a price down- that can be awkward
• Sellers love to move items in bulk, so instead of asking about individual prices, ask how much for the whole collection of items you want. You'll likely get a better deal.
• Start your negotiation at a reasonable price. If someone is selling something for $50, don't offer $5. Start a $30 and go from there. If they won't budge on the price and you don't feel like it's worth it, be willing to walk away.

What strategies do you use when you shop at garage sales?

Sources: New York Times / Gemr / The Fiscal Times / Daily Mail / Money Crashers