Aluminum round pipe ducting

New Rigid Aluminum round pipe ducting:
(a) 4″ diameter x 3 ft length @ $25.00 per piece
(b) 5″ diameter x 3 ft length @ $35.00 per piece

(c) 6″ diameter x 3 ft length @ $45.00 per piece
(d) 7″ diameter x 3 ft length @ $55.00 per piece
(e) 8″ diameter x 3 ft length @ $65.00 per piece