It was always gonna become Palau Vs.....I think partly because palau is difficult ish to get to people who have been will critique it, more than say if it was 3 hrs from Manila by bus lol! Re the flights I still think its monopolised by one airline. SAMs tours and fish n fins I don't think can get you cheaper flights. There are flights from Taipei, Seoul and Tokyo I think with other airlines but I don't think that will help you from oz. think Manila is still the cheapest option!
Palau is well worth it, tons of mantas in ulong channel, bull sharks at Pelileu cut and satans corner, and sharks everywhere. IMO blue corner, blue hole, big drop off etc are all excellent sites but not actually the best ones! But it's all subjective....if nothing turns up then it wouldn't b worth the trip! But you will be pushed to find better dive site scenery!!!