Cheapest priced copy (Planechase Anthology): $0.59 at Card Kingdom, near mint, their price list as of .
Farsight Mask 
Artifact · Uncommon · Mirrodin · #170
Whenever a source an opponent controls deals damage to you, if this artifact is untapped, you may draw a card.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $0.59 to $2.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Mirrodin | 170 | Uncommon | $0.69 | $2.99 |
| Planechase 2012 | 109 | Uncommon | $0.69 | — |
| Planechase Anthology | 109 | Uncommon | $0.59 | — |
4 rulings from Wizards of the Coast
- 1 December 2004Each instance of each creature’s combat damage is counted separately. If three creatures with double strike attack you and all of them are unblocked, you may draw up to six cards.
- 1 December 2004You draw no more than one card each time a source an opponent controls damages you, no matter how much damage the source deals.
- 1 December 2004This triggers each time a source an opponent controls deals damage to you. If the same source deals damage more than once in a turn, it triggers for each of those times.
- 1 December 2004Farsight Mask must be untapped both when the damage is dealt and when you would draw the card.