6 printings of Mitotic Slime
They range from $0.34 to $2.29 — a 7× difference for a card with the same name. The set code and collector number printed along the bottom edge are what tell them apart.
| DCI Promos | DCI 53 | — |
| Secret Lair Drop | SLD 2815 | $2.29 |
| Planechase Anthology | PCA 67 | $0.42 |
| Planechase 2012 | PC2 67 | $0.40 |
| Magic 2011 | M11 185 | $0.34 |
Not sure which one you are holding? OtterDex reads the set code and collector number off the card and tells you.