What makes a card valuable

Age and print run set the ceiling. A 1952 Topps Mantle is valuable partly because it is scarce by age and survival and partly because of who it depicts. A 2020 Panini Prizm Luka Doncic Silver PSA 10 is valuable because of a combination of the player's trajectory, the parallel's relative scarcity within the print run, and the grade. Condition and grade is the most lever-able variable

The grading companies assess cards on centering, corners, edges, and surface. A card with perfect corners but off-center printing will grade lower than a centered card with minimal surface wear. Learning to grade accurately before submitting is a skill that saves money and time. Rookie cards command a premium because they mark the beginning of a career

The most valuable rookie card is almost always the one from the player's first nationally distributed set. Autographs and relics add authenticity-dependent value. A certified autograph from a player who signs rarely is worth more than the same card from a player who signs everything.

CollectorGrade take

Centering is the most common reason a card grades lower than its owner expects. Learn to identify off-center cards before you submit. The cost of grading a card that comes back a 7 when you expected a 10 is the same as submitting a genuine 10.