Cheapest priced copy (Kaladesh): $0.35 at Card Kingdom, near mint, their price list as of .
Night Market Lookout 
Creature — Human Rogue · 1/1 · Common · Kaladesh · #95
Whenever this creature becomes tapped, each opponent loses 1 life and you gain 1 life.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Kaladesh | 95 | Common | $0.35 | $0.79 |
3 rulings from Wizards of the Coast
- 20 September 2016This is a triggered ability, not an activated ability. It doesn't allow you to tap Night Market Lookout whenever you want; rather, you need some other way of tapping it, such as by attacking.
- 20 September 2016For the ability to trigger, Night Market Lookout has to actually change from untapped to tapped. If an effect attempts to tap it, but it was already tapped at the time, this ability won't trigger.
- 20 September 2016In a Two-Headed Giant game, Night Market Lookout's ability causes the opposing team to lose a total of 2 life.