(NEXSTAR) — You’ve likely heard the phrase “collect them all!” when it comes to toys, cards, bobbleheads, or almost anything else in a series, like Beanie Babies. You may still have some or all of whatever you collected as a kid today, but they may be better at collecting dust than dollars for you.

Many of those toys and other items were released in the late 1900s, a time in which mass production was underway. Mass production allowed customers to collect each piece of the line, and then some (how many times did you get a repeat toy in your Happy Meal, or a duplicate Pokemon card?).

This also means that while you were busy “collecting them all,” creating a set of items that were surely destined to be valuable in the future, so were many others.

“You know, people just seem to think that since something is collectible, it automatically is valuable, and that’s not always the truth,” Jordan Hembrough, toy expert and host of the show “Toy Hunter,” tells Nexstar.

Beanie Babies, Cabbage Patch Kids, Barbies, Pokemon cards, and comic books are prime examples of this, Hembrough explains. These lines of toys and collectibles are the most common people believe will be worth a lot of money but aren’t.

Comic books are one of the hotter items for collectors right now.

“Unfortunately, you know, a lot of people are collecting comic books from the 1980s and even the 1970s,” Hembrough says. “Those comic books really aren’t the ones that are super valuable though.”

Those from the decades prior – the 1940s, ’50s, and ’60s – are usually more valuable.

The same goes for another popular item for collectors: baseball cards.

Cards released during the ’80s and ’90s were, like many other collectibles, manufactured during a time of mass production, Mike Provenzale, a production manager with Heritage Auctions tells Nexstar. While the tides are changing for some of these cards from the ‘Junk Wax Era,’ that’s not the case for other items.

Speaking of sports memorabilia, Provenzale says most modern autographs aren’t worth as much as you’d hope either. This is largely because there are so many out there, he explains. Every time an athlete signs anything, they’re essentially devaluing themselves.

Having more signatures on one item – like a team-autographed football – doesn’t typically increase its monetary value because collectors usually want just one signature, according to Provenzale.

And if you get ahold of free memorabilia for attending a game, like a bobblehead, Provenzale says it’ll have more value in the parking lot for someone who didn’t get one than in the collector’s market later on.

There are some exceptions within these over-collected categories, though.

According to Hembrough, “the collectibles industry is very, very cyclical.” If roles or franchises are revived, this can help older collectibles become desirable again. He points to “Star Wars,” “Raiders of the Lost Ark,” and “Jurassic Park.”

On the other hand are toys that were previously relatively popular but have lost their value recently. Among those are toys from the “Teenage Mutant Ninja Turtles” franchise, which were “really hot five or six years ago,” Hembrough explains.

When it comes to autographed sports memorabilia, while most modern signatures aren’t worth much, select athletes can be special. Derek Jeter, Michael Jordan and Tom Brady are great exceptions to this because they have exclusive deals to sign only for specific companies, leading to fewer of their signatures being available.

If your favorite athlete and their team win the championship game, know that the championship gear you run out to get likely won’t be worth much more than what you pay for it at the store. Instead, championship gear from the losing team, which is usually donated, is more likely to have a kitsch value, Provenzale explained.

Regardless of whether you find yourself with a collectible like a Happy Meal toy or a Beanie Baby or one of these toys Hembrough says is worth hanging onto, both Hembrough and Provenzale recommend researching your item. You can search your item on Google or eBay, for example, to see how others like yours are selling. You may also want to consider taking your items to local collector shops or auction houses for an expert to review its value.