Cheapest priced copy (Bloomburrow Commander): $0.79 at Card Kingdom, near mint, their price list as of .
Body of Knowledge 
Creature — Avatar · */* · Rare · Duskmourn: House of Horror Commander · #112
Body of Knowledge's power and toughness are each equal to the number of cards in your hand.
You have no maximum hand size.
Whenever this creature is dealt damage, draw that many cards.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
4 printings · $0.79 to $7.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Bloomburrow Commander | 163 | Rare | $0.79 | — |
| Commander Legends | 59 | Rare | $0.79 | $0.99 |
| Commander Legends | 631 | Rare | $2.79 | $7.99 |
| Duskmourn: House of Horror Commander | 112 | Rare | $0.79 | — |
3 rulings from Wizards of the Coast
- 10 November 2020Creatures may be dealt damage greater than their toughness. For example, if Body of Knowledge is a 3/3 creature and a source deals 5 damage to it, you'll draw five cards. Note that if Body of Knowledge is dealt lethal damage, it dies before the cards are drawn, meaning they won't raise Body of Knowledge's toughness in time to save it.
- 10 November 2020As long as Body of Knowledge is in your hand, its ability will count itself.
- 10 November 2020The ability that defines Body of Knowledge's power and toughness applies in all zones, not just the battlefield.