Every PokeStop card we price, most valuable first. Prices are what copies actually sold for, updated daily.
What a PokeStop card is worth
The most valuable PokeStop on this list is PokeStop (Shao Tong Yen) from World Championship Decks at $1.05£0.79€0.92, and the 3 priced copies across 2 sets are worth $2£1€2 together. Most of that sits in a handful of printings: the older the set and the scarcer the print run, the wider the gap to the rest.
reverse holo printings are priced separately from the standard card, because they do not trade at the same money.
If you are trying to identify which PokeStop you have, the set name is printed on the card and the collector number sits in the bottom corner. Open the card here and the page carries every printing of it, the graded prices, and whether grading the copy is worth the fee. Sets to start with: World Championship Decks, Pokemon GO.