Which Mallow do you have?
Same name, 47× the price: $1.75 to $83 raw. The difference is printed on the card — it is just not somewhere most people think to look.
Alolan Moonlight · #055
Check the set symbol in the lower right of the illustration, and the copyright year along the bottom edge. Those two identify the print run on every card that has them.
$83
34% gem
SM-P Promos · #246
Check the set symbol in the lower right of the illustration, and the copyright year along the bottom edge. Those two identify the print run on every card that has them.
$14
74% gem
GX Battle Boost · #107
Check the set symbol in the lower right of the illustration, and the copyright year along the bottom edge. Those two identify the print run on every card that has them.
$7.99
56% gem
Alolan Moonlight · #049
Check the set symbol in the lower right of the illustration, and the copyright year along the bottom edge. Those two identify the print run on every card that has them.
$2.25
100% gem
Guardians Rising · #127
Check the set symbol in the lower right of the illustration, and the copyright year along the bottom edge. Those two identify the print run on every card that has them.
$1.75
50% gem
We have no hand-checked note for these printings yet, so the guidance above is the general rule rather than something specific to this card.
Prices are raw market value. Click a printing for its full grading verdict — the gem rate, the fees and whether it beats selling raw.