Yes, SAGAS is a Scrabble word!

Letter values in Scrabble US: S 1, A 1, G 2, A 1, S 1.

Is it a valid word?

SAGAS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a narrative telling the adventures of a hero or a family; originally (12th to 14th centuries) a story of the families that settled Iceland and their descendants but now any prose narrative that resembles such an account