The odds are against your sports memorabilia being "worth something someday."

With each generation that comes of age and attempts to unload a lifetime's worth of team merchandise, promotional items, cards, autographs and other items, there's the realization that much of the value behind those items was sentimental. That they were totems of your youth: A tie to an experience, an event or the person who introduced you to the game, but they're rarely good investments.

That sentiment fuels a $12 billion licensed sports merchandise business and a $1.5 billion autograph market, according to SportsMemorabilia.com. Baseball alone accounts for 26% of all memorabilia sales, but still ranks a close second to the 34% of revenue generated by National Football League items. That hasn't exactly discounted baseball's nostalgia market, as autographs from Cal Ripken Jr. and Willie Mays at memorabilia conventions can cost $150 to $300 apiece.

However, those are living sports legends whose lives can still alter the monetary value of those signatures with even a minor misstep. It's a lucrative prospect for both the players and their estates, with former Green Bay Packers coach Vince Lombardi's son selling off notes and a championship ring and Pittsburgh Pirates slugger Willie Stargell's wife selling off items including his 1979 World Series ring and Most Valuable Player trophy earlier this year.

However, it can be a tough market for fans to navigate, especially with shady dealers facing federal investigation for rigging auctions, bidding up their own items and tampering with collectibles without disclosing changes. Fraud is so common in the memorabilia world that Peter J. Nash, known to hip-hop fans as Pete Nice from late-'80s, early '90s group 3rd Bass, has dedicated an entire second career to it on his blog Hauls Of Shame.

A combination of nostalgia, a growing buyer base, increasing expendable income and, yes, fraud driving up prices for the most sought after items into the millions, with even slightly lesser pieces regularly fetching six figures. Yet even big ticket items, like those related to baseball legend Babe Ruth that were recently sold at auction by actor Charlie Sheen can come under scrutiny for alleged fraud. Those high stakes make it more important than ever for fans to distinguish sentimental value from sales price and to make sure their memorabilia comes with as much provenance and certification as possible.

That said, there are some items out there that are just never going to be worth anything. We went through myriad options for memorabilia and found 10 that are absolutely worthless monetarily. If you don't absolutely love these items, good luck unloading them.

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