Ken Griffey Jr. Card Market Heats Up

Ken Griffey Jr. is one of the hobby's most collectible athletes. For 80's kids, Griffey is a source of nostalgia. Now, the kids from the 80s are grown up and have some expendable income. It's driving prices up for some of Griffey's nicest cards.
The Card Ladder Griffey index shows that his card prices have increased by more than 11% over the past three months. The famous 1989 Upper Deck Star Rookie has gone up in value by 15% over the past three months. Below are some other cards with recent notable sales.
RELATED: Most Expensive Ken Griffey Jr. Card Ever Sets Record
1. 2009 Bowman Chrome Superfractor 1/1 BGS 9.5
This Superfractor sold on May 4 for $21,300 on eBay. The card is in BGS Gem Mint condition, which makes it a true Griffey grail.
2. PSA 10 1998 Topps Finest The Man Refractor #'d 20/75
A PSA 10 Griffey Refractor from the '90s? It's as good as gold. According to BaseballCardPedia, The Man Refractors had 1:793 wax pack odds and 1:367 odds in jumbo boxes. Hobby boxes contained 24 packs per box with six cards per pack. Home Team Advantage/Jumbo boxes had 12 packs per box, containing 13 cards per pack.
This card sold on March 24 for $18,988 on eBay, receiving 45 bids. This card is one of four PSA 10s - another PSA 10 sold in July 2020 for $7,224.
3. PSA 10 1989 Upper Deck #1 Ken Griffey Jr. with AUTO 10
Unsigned versions of this card in PSA 10 have sold for an average of $2,646 in the past three months, according to Card Ladder. With the addition of a perfect autograph, the card jumps to $19,100, as this card did when it sold on May 13 on eBay.
Another PSA 10 with a Gem Mint autograph sold for $18,852 three weeks earlier. It makes one wonder how many people would risk buying a PSA 10, cracking it out of the slab, getting a Griffey autograph, and resubmitting it for grading. Note to the reader: this is not a recommendation to do that.