12 printings of Oblivion Ring
They range from $0.18 to $0.48 — a 3× difference for a card with the same name. The set code and collector number printed along the bottom edge are what tell them apart.
| Friday Night Magic 2009 | F09 11 | — |
| Duel Decks: Knights vs. Dragons | DDG 34 | $0.48 |
| Commander 2011 | CMD 23 | $0.36 |
| Magic 2012 | M12 27 | $0.26 |
| Magic 2013 | M13 22 | $0.25 |
| Lorwyn | LRW 34 | $0.23 |
| Modern Masters 2015 | MM2 29 | $0.23 |
| Planechase | HOP 4 | $0.22 |
| Duel Decks: Venser vs. Koth | DDI 28 | $0.21 |
| The List | PLST LRW-34 | $0.19 |
| Shards of Alara | ALA 20 | $0.18 |
Not sure which one you are holding? OtterDex reads the set code and collector number off the card and tells you.