Yes, perk is a Scrabble word!
...and is worth 10 points in Scrabble, and 11 points in Words with Friends
perk
Verb
1. Gain or regain energy
Noun
1. An incidental benefit awarded for certain types of employment (especially if it is regarded as a right)
What Scrabble words can I make with the letters in perk?
3 Letter Words
2 Letter Words