I was there in February on the Dutch side. I asked a fellow passenger who had taken a cab to Orient and she said she paid $18 each way. Another lady told me she paid $25. I* am sure you would be able to neogiate a price with a driver. If you are docking in the Dutch side the cabs will be right at the dock.
RCCL - Enchantment of the Seas - Eastern
Carnival - Fascination X2 - Southern
Carnival - Tropicale - Western
Celebrity - Millennium - Eastern
Celebrity - Century - Western
Princess - Caribbean - Eastern