Cheapest priced copy (Double Masters): $0.39 at Card Kingdom, near mint, their price list as of .
Sandstone Oracle 
Artifact Creature — Sphinx · 4/4 · Uncommon · Commander 2015 · #52
Flying
When this creature enters, choose an opponent. If that player has more cards in hand than you, draw cards equal to the difference.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
9 printings · $0.39 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 285 | Uncommon | $0.39 | $0.79 |
| Commander 2015 | 52 | Uncommon | $0.69 | — |
| Commander Anthology Volume II | 213 | Uncommon | $0.59 | — |
| Commander Masters | 406 | Uncommon | $0.59 | $0.79 |
| Commander Legends | 336 | Uncommon | $0.49 | $0.79 |
| Iconic Masters | 227 | Uncommon | $0.59 | $0.79 |
| The List | C15-52 | Uncommon | $0.49 | — |
| The List | CM2-213 | Uncommon | $0.59 | — |
| Zendikar Rising Commander | 116 | Uncommon | $0.39 | — |
2 rulings from Wizards of the Coast
- 10 November 2020You choose an opponent while Sandstone Oracle's ability is resolving. No player may take actions between the time you make this choice and the time you draw cards.
- 10 November 2020To draw cards equal to the difference, first determine how many cards you'll draw, then draw that many cards, as modified by replacement effects. For example, if you have two cards in hand and the chosen opponent has five, Thought Reflection will cause you to draw six cards instead of three.