you do have a piece by Royal Arden Hickman prior to his working for Haeger.Before the Haeger union, Hickman ran his own pottery company named RA Art Pottery of California begining in the 1930’s. Before that he worked out of his own garage with his wife.
1934 Royal Arden Hickman is employed by Haeger, 1938 becomes chief designer for Royal Haeger line. So your piece dates 1930-1934. 1944 Royal Arden Hickman leaves Haeger Potteries. As far as value would need photos of your piece.