Cheapest priced copy (Assassin's Creed): $47.99 at Card Kingdom, near mint, their price list as of .
Sword of Feast and Famine 
Artifact — Equipment · Mythic · Mirrodin Besieged · #138
Equipped creature gets +2/+2 and has protection from black and from green.
Whenever equipped creature deals combat damage to a player, that player discards a card and you untap all lands you control.
Equip {2}
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
11 printings · $47.99 to $499.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 296 | Mythic | $57.99 | $69.99 |
| Double Masters | 364 | Mythic | $129.99 | $129.99 |
| Assassin's Creed | 99 | Mythic | $47.99 | $49.99 |
| Assassin's Creed | 124 | Mythic | $64.99 | $59.99 |
| Assassin's Creed | 261 | Mythic | — | — |
| Judge Gift Cards 2014 | 6 | Rare | — | $139.99 |
| Mirrodin Besieged | 138 | Mythic | $59.99 | $129.99Out of stock |
| Modern Event Deck 2014 | 10 | Mythic | $57.99 | — |
| Kaladesh Inventions | 28 | Special | — | $499.99 |
| Grand Prix Promos | 2016b | Rare | — | — |
| The List | 2XM-296 | Mythic | $54.99 | — |
2 rulings from Wizards of the Coast
- 7 August 2020You'll untap all lands you control even if the player can't discard a card.
- 7 August 2020You can tap your lands for mana while the triggered ability is on the stack. However, you'll lose any mana you produce this way if you don't spend it before the end of the current combat damage step.