I am planning to go for a conference in Cairns in June this year, and I am hoping to do a 3-4 day live-aboard scuba diving trip afterward. There are numerous companies organizing these kind of trips from Cairns directly, but I was wondering if it may be better (either cheaper overall or the diving would be in more interesting locations) if I started the trip from some other location?
There is significant tourism infrastructure in Cairns. This includes the international airport and a booking agency on every corner. There is good competition amongst operators. I do not think you will find better value for money in other locations up or down the coast.
If you are looking to get away from the tourist areas, you could consider staying on an island (e.g. Heron Island) and doing multiple day scuba trips.