Cocogarden Cocopeat Brick - Expands To 3.5 Kg Powder This is as good a place as any to start. Carnivorous plants don't need a lot of medium, so this should be plenty to get started.
COCOPEAT Block - EXPANDS to 75 litres of Coco PEAT Powder This is a bigger brick. Probably better if you also grow other plants in containers. Works out cheaper.