Hey Dave ,
Cygnet Bay is cheapest for crew transfer, road or plane , Horizontal Falls seaplane will do transfers but around 700 a seat back to Broome, I have chartered a Mallard from Pasparley Darwin to king George for around $8000 . You might get a barge run back to Derby from kempy. Avair gave me a quote for cockatoo for about 5000 to Broome pay load 1100kg max 13 pax ?KAS will do heli transfers As well depending how many crew 4 /6 ..
Hope that helps
Elli