18 printings of Boros Signet
They range from $0.52 to $15.21 — a 29× difference for a card with the same name. The set code and collector number printed along the bottom edge are what tell them apart.
| Secret Lair Drop | SLD 291 | $15.21 |
| Ravnica: City of Guilds | RAV 255 | $2.03 |
| Ravnica Remastered | RVR 251 | $1.88 |
| Commander 2020 | C20 239 | $1.77 |
| Phyrexia: All Will Be One Commander | ONC 126 | $1.70 |
| Commander Masters | CMM 942 | $1.69 |
| Planechase | HOP 107 | $0.96 |
| Commander Anthology | CMA 212 | $0.86 |
| Ravnica: Clue Edition | CLU 220 | $0.72 |
| Commander 2011 | CMD 243 | $0.71 |
| Commander Anthology Volume II | CM2 176 | $0.66 |
| Commander 2017 | C17 205 | $0.65 |
| GRN Guild Kit | GK1 97 | $0.62 |
| Tarkir: Dragonstorm Commander | TDC 314 | $0.60 |
| Commander Legends | CMR 459 | $0.54 |
| Commander 2015 | C15 247 | $0.52 |
| Modern Masters 2017 | MM3 217 | $0.52 |
Not sure which one you are holding? OtterDex reads the set code and collector number off the card and tells you.