Going to Langkawi in a Short While

I am going to Langkawi by Firefly which was booked and confirmed last night. It takes about 30 minutes to arrive from Penang Airport to Langkawi's Airport. We need to take measurement for a sports court for a customer before flying back the next day on Sunday. Most likely, we will stay overnight in Langkawi after doing the necessary. This is a short business trip. And I just found out from my sister that a return trip by boat is about RM100 plus. Had I known that earlier, we would have taken the boat and save us about RM620 for 2 persons return by flight plus airport tax.