8 printings of Gaseous Form
They range from $0.04 to $0.54 — a 14× difference for a card with the same name. The set code and collector number printed along the bottom edge are what tell them apart.
| Legends | LEG 59 | $0.54 |
| The List | PLST EMA-51 | $0.34 |
| Fifth Edition | 5ED 90 | $0.24 |
| Classic Sixth Edition | 6ED 71 | $0.12 |
| Tempest | TMP 65 | $0.11 |
| Fourth Edition | 4ED 74 | $0.07 |
| Eternal Masters | EMA 51 | $0.04 |
Not sure which one you are holding? OtterDex reads the set code and collector number off the card and tells you.