Salmon fishermen agreed to go back to work after reaching a compromise with wholesale buyers on the price of fish. A spokesman for the Half Moon Bay Fisherman’s Marketing Assn. said the agreement calls for a price of $2.50 a pound for fish of 11 pounds or more, $2.30 for fish of 7 to 11 pounds and $1.90 for smaller fish. The agreement affects about 1,500 salmon trollers from Fort Bragg, Bodega Bay, Sausalito, Oakland, San Francisco and Moss Landing. The fishermen tied up their boats last Friday and refused to sail when some buyers demanded a price cut.