These duty labels are incredibly rare as they were designed to be destroyed when the pack of coffee was opened. As a result you're only likely to see specimen copies, although there's an actual used one shown here.
(01) ½d Blue (1882)
Market Value: £100.00
(02) 1d Carmine (1882)
Market Value : £40.00
(05) ¼d on ½d Blue (1915)
Market Value : £125.00