Cheapest priced copy (GRN Guild Kit): $0.79 at Card Kingdom, near mint, their price list as of .
Grave-Shell Scarab 
Creature — Insect · 4/4 · Rare · Ravnica: City of Guilds · #211
{1}, Sacrifice this creature: Draw a card.
Dredge 1 (If you would draw a card, you may mill a card instead. If you do, return this card from your graveyard to your hand.)
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
2 printings · $0.79 to $1.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| GRN Guild Kit | 63 | Rare | $0.79 | — |
| Ravnica: City of Guilds | 211 | Rare | $0.79 | $1.99 |
7 rulings from Wizards of the Coast
- 1 October 2005You may sacrifice Grave-Shell Scarab to pay for its first ability, then replace that draw using the Scarab's dredge ability. The result is that the top card of your library is put into your graveyard and Grave-Shell Scarab returns to your hand (after a brief trip to the graveyard).
- 12 January 2024One card draw can't be replaced by multiple dredge abilities.
- 12 January 2024You can't attempt to use a dredge ability if you don't have enough cards in your library.
- 12 January 2024If you're drawing multiple cards, each draw is performed one at a time. For example, if you're instructed to draw two cards and you replace the first draw with a dredge ability, another card with a dredge ability (including one that was milled by the first dredge ability) may be used to replace the second draw.
- 12 January 2024Dredge can replace any card draw, not only the one during your draw step.
- 12 January 2024If an effect puts a card into your hand without specifically using the word "draw," you're not drawing a card. Dredge can't replace this event.
- 12 January 2024Once you've announced that you're applying a card's dredge ability to replace a draw, players can't take any actions until you've put that card into your hand and milled cards.