Yes, ORTHOEPIST is a Scrabble word!

Letter values in Scrabble US: O 1, R 1, T 1, H 4, O 1, E 1, P 3, I 1, S 1, T 1.

Is it a valid word?

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

a practitioner of orthoepy (especially one of the 17th or 18th century scholars who proposed to reform English spelling so it would reflect pronunciation more closely)