NBA
When most people think of expensive sports cards, baseball cards typically come to mind. The pure age of the MLB means their cards have been around a lot longer, which should make them more valuable because of the scarcity of something so old, such as a Babe Ruth card, right?
Not quite.
The NBA has some big sellers in its own right and the answer may surprise you when it comes to who takes the top sale. Michael Jordan? Kareem Abdul-Jabbar? LeBron James?
Great guesses, but the baby-faced assassin himself takes the top spot - Stephen Curry. An autographed Curry National Treasures Logoman rookie card sold on July 6, 2021, for the cheap price of just $5.9 million. The card received an 8 and the autograph a 10 by PSA.
NFL 
Kansas City Chiefs Quarterback Patrick Mahomes is familiar with setting records. He continued this trend off the field on July 28, 2021, when a 2017 National Treasures NFL Shield Patrick Mahomes rookie autographed card sold for an impressive $4.3 million.
The card received a grade of 8.5 by Beckett. The card is quite literally one of a kind. So was it the scarcity of the card? Or was it the massive talent and potential of Mahomes as a generational athlete, or a combination of the two?
That is to be decided by the people who have $4.3 million to spend on a trading card.
NHL
The NHL is, by far, the least popular of these leagues. If one doesn't know much about hockey, they probably wouldn't expect any sale even close to the MLB, NBA, or NFL.
Allow us to introduce Wayne Gretzky, humbly nicknamed "The Great One", if you haven't heard of him already. The NHL's all-time leader in goals and assists set another record for the sport.
Gretzky's 1979 O-Pee-Chee rookie card graded a PSA 10 sold for $3.75 million in May 2020. The only other PSA 10 of this card sold months prior in December 2020 for $1.29 million. Suffice to say, the market for sports cards has been on the rise.
Gretzky was so good at hockey that he is in the same tier with current megastars in much popular leagues 23 years after retirement. Impressive stuff from the undisputed G.O.A.T of the ice.
MLB 
The T206 Honus Wagner baseball card is undoubtedly the most famous sports card of all time. It's considered the holiest of holy grails for sports cards collectors because it is insanely scarce. It holds four of the top 10 all-time highest sales for cards, including the top spot.
In August 2021, an SGC 3 sold for $6.6 million. This Wagner card has been selling for record highs, even before the latest boom in the market.
Of all the old greats of baseball, it is not Babe Ruth or Lou Gehrig who holds the top spot. Instead, the man only famous at this point for having a rare card holds the record and will probably keep setting new ones.
Conclusion
The market for collectibles is always going to ebb and flow. Prices for semi-key issue comics and mid-tier grail sports cards are going to be volatile for the rest of time. One thing stays constant, though. The "blue chips," for lack of a better term, are never going to stop gaining value.
Whether it is an Amazing Fantasy #15 or a T206 Honus Wagner card, grails only have one way to go: up. At the moment, these are the all-time highs in each major league, but in another few decades, these will seem like steals.
Will another league overtake MLB as the top card? Tell us your thoughts in the comments!
