Expected Winnings of a Repeat-Stop Dice Game

You have a 6-sided die with faces $(1, 2, 3, 1, 2, 3)$ -- so each of the values $\{1, 2, 3\}$ appears with probability $\frac{1}{3}$. You roll repeatedly. Each roll pays you coins equal to the face value shown. The game ends the moment you roll the same value as the previous roll. What is the expected total payout?