The 1991 Upper Deck baseball card set was groundbreaking in the hobby for several reasons. It was the first time that Upper Deck, a competitor to Topps, was licensed by Major League Baseball to produce official baseball cards. This allowed them to use high quality photography and player bios/stats directly from the MLB, a level of authenticity previous challenger brands like Score and Donruss could not achieve. It also broke the traditional model of only having one licensed baseball card company.

Another notable aspect of the 1991 Upper Deck set was that it contained 702 cards, making it the largest sports card set produced at the time. The vast number of cards meant that Upper Deck could include parallels, variations, rookie cards, and other subsets to excite collectors. Perhaps most importantly though was the use of innovative imaging and printing techniques that resulted in much higher production quality compared to competitors. These photographic style cards really made the players pop off the cardboard.

All of these factors would drive collector interest and demand for 1991 Upper Deck cards sky high. But it’s taken 30 years for the true value of many of these cards to be realized as they’ve left the hands of the original owners and entered the vintage/investment card market. Here is a closer look at some of the most valuable 1991 Upper Deck baseball cards today based on PSA 10 gem mint graded prices:

Ken Griffey Jr. Rookie Card (#1) – As one of the most iconic rookie cards ever, the Ken Griffey Jr. from 1991 Upper Deck is still highly sought after by collectors. In a PSA 10 condition, it routinely sells for $3,000-5,000. Even PSA 9s go for $1,000-2,000 showing its staying power.

Frank Thomas Rookie Card (#642) – Frank Thomas would go on to have a Hall of Fame career and his rookie is one of the key cheap91 UD rookies. PSA 10s sell in the $1,000-2,000 range with PSA 9s around $500.

Chipper Jones Rookie Card (#221) – As a career-long Atlanta Brave and 2008 World Series hero, Chipper Jones rookie maintains strong demand. PSA 10s have sold for up to $1,000 with PSA 9s in the $300-500 range.

Todd Van Poppel Rookie Card (#629) – Van Poppel was a top pitching prospect but didn’t pan out in the majors. Still, his error-free 1990s rookie card is highly collectible graded. PSA 10s have cracked $1,000.

Tom Glavine Rookie Card (#313) – Two-time Cy Young Award winner Glavine is represented with a nice rookie in 1991 UD. PSA 10 sales are around $800 while PSA 9s bring $300-400.

Paul Molitor Back Coat Variation (#289) – One of the most desired variations is Molitor wearing his jersey backwards on the front of the card. PSA 10 examples are $500-800.

Mark McGwire Insert (#646) – Featuring dramatic photography of McGwire swinging, this iconic insert has sold PSA 10 for over $500. Even PSA 9s bring $200-300.

Will Clark Studio (#688) – Clark posed for unique Upper Deck studio photography that makes this a very collectible and aesthetically pleasing card. PSA 10s have sold for $700-800.

Cal Ripken Jr. Studio (#691) – Much like the Will Clark, Cal Ripken’s unique studio variant remains a popular high-end 91 UD card. PSA 10s have cracked $600.

Matt Williams Home Run Leaders Insert (#600) – Showing highlight stats like HR and RBI totals, these inserts are scarce and desirable. PSA 10 has sold for over $500.

Dennis Eckersley Closer Portrait (#640) – Portraying “Eck” in his signature role, this card pays tribute to one of the game’s great relievers. PSA 10s over $400.

Nolan Ryan Milestones/Special Achievements Insert (#607) – Honoring Ryan’s career accomplishments, it’s a highly coveted piece for any Ryan PC. PSA 10 over $300.

While 1991 Upper Deck lost significant value during the ‘junk wax’ era crash of the 1990s, savvy collectors who retained high-grade samples of rookie cards, stars, and inserts from the innovative set are now being handsomely rewarded. 30 years later, the true historic nature and quality of 1991 UD is being recognized, making many of its cards prized vintage investments today. For those who procure a Frank Thomas, Chipper Jones, or Cal Ripken Studio PSA 10, huge long-term appreciation could still be ahead.