The component with the lowest price in the IGNITION COIL schematic is the Nut,hex Cap 6mm.
Parts such as the Ignition Coil: Coil Comp, Plug Hole, Nut,hex Cap 6mm, Plug Hole Seal, Spark-plug Pkj20c are included in the Civic 2003 (3) 4dr Ex (ka) Ignition Coil parts fiche.
The Civic 2003 (3) 4dr Ex (ka) Ignition Coil consists of four pieces with the Coil Comp, Plug Hole being the most expensive.