Jimi Hendrix, John Mayall and Albert King played a series of concerts at San Francisco's storied Fillmore and Winterland music venues in February 1968; the poster advertising the shows featured a bloodshot eyeball flying through a ring of fire.

"It was totally cool and a your-mother-would-shriek-if-she-saw-it kind of thing," said Ben Marks, a collector of vintage rock posters.

If you were lucky enough to be there, you have the memories. If you nabbed a poster, you may have much more.

A first printing of the poster in mint condition might sell for $10,000, said Marks, senior editor at Collectors Weekly, a San Francisco-based website that's part auction, part social media and part news site.

It's just one example, albeit an extreme one, of the market for boomer collectibles. Toys, music, furniture, sporting goods, politics — many of the things that the baby boom generation cherished as children and young adults now have monetary value.

According to Collectors Weekly, a 1969 Hot Wheels custom T-Bird recently sold on eBay for $502. A 1959 Sony transistor radio went for $256 and a 1966 Barbie doll brought $710.

The common thread among these items is condition: They're in original boxes or are in like-new or lightly used shape. That's usually the linchpin of any collectible, dealers say.

Take that Jimi Hendrix poster.

Marks said: "I definitely remember that poster on people's walls, but they were putting it on their walls with tape or thumbtacks, and that kind of thing completely devalues those pieces."

He said any collectibles market usually will resemble a pyramid: A handful of items at the very top are worth a boatload of money, then there's everything else.

Still, even items with lots of wear can sell. A Color Magic Barbie with almost no hair sold on eBay for $211. A third printing of the Hendrix "flying eyeball" poster with condition issues sold for $99.

It's all supply and demand, said Penny Simonson, a longtime dealer in Spokane, Wash.

Boomers reliving youth

Generally, items from the '50s, '60s and '70s are hot now, she said.

The high-demand toys change over the years, but the phenomenon remains the same, said Joe Morabito, owner of Main Street Toys, who has been selling vintage toys via the Internet (www.mainstreettoys.com) and from a shop in northeast Minneapolis since 1989.

"As each generation thinks back on the good times they had as youngsters and gets to the point where, hopefully, they have some discretionary income, they want to buy those good memories back," he said.

"What changes with each generation is the type of toys. I used to get a lot of requests for cast-iron toys [which remained popular through the 1940s], but I don't get those anymore. Now it's the guy who remembers the Tonka toy he opened on Christmas morning. Those are the good times that we like to remember."

High-end antiques are out of favor among younger collectors, Simonson said. Something she called "fascinating junk" is in.

Dianna Chelf, of Spokane's Two Women Vintage Goods, said colored Pyrex mixing bowls are an example. Nested sets of these bowls, which typically came in primary colors, can sell for $50 or even $100.

"Whoever would have thought as we were putting them in the dishwasher — ruining them — that someday they'd be worth something?" she said.

Joshua Scott specializes in vintage toys at Spokane's Time Bomb store. He said toys based on Hanna-Barbera cartoons sell well, such as "The Flintstones," "Yogi Bear" and "The Jetsons." Toys based on 1960s TV series such as "The Addams Family" and "The Munsters" are so popular "that stuff is getting harder and harder to find," he said.

Marks wonders what will happen to the boomer collector market over the next few years.

"There's a lot of this stuff in people's garages, closets and attics, and it's only a matter of time before all this stuff starts getting released," he said.

But maybe it doesn't matter, he said.

"That's the thing that's cool about stuff," Marks said. "It'd be nice to get the extra $50 because you find something in your garage, but to me what's really interesting is what these things tell us about what we are and where we came from."

Staff writer Jeff Strickler contributed to this report.