8 printings of Youthful Knight
They range from $0.05 to $0.30 — a 6× difference for a card with the same name. The set code and collector number printed along the bottom edge are what tell them apart.
| Tenth Edition | 10E 62★ | — |
| Anthologies | ATH 19 | $0.30 |
| Archenemy: Nicol Bolas | E01 22 | $0.27 |
| Stronghold | STH 25 | $0.19 |
| Tenth Edition | 10E 62 | $0.14 |
| Throne of Eldraine | ELD 37 | $0.06 |
| Modern Masters 2017 | MM3 29 | $0.05 |
Not sure which one you are holding? OtterDex reads the set code and collector number off the card and tells you.