HABBARIDS OF SIND: 'Umar, ca. 854-875, AR damma (0.51g), A-4527var, Fishman-HS—, obverse legend Allah / 'umar wa b / bihi yuntasir, crescent below // muhammad / rasul / Allah wa / bihi yuntasir, crescent above, with some crudeness to the legends, especially the word yuntasir and the extra "b" before bihi, probably an emergency issue from an alternative mint, VF, RRR.
Estimate: USD 100 - 120