So you know, the Port Douglas/Cairns area is very small. To Cairns City/Palm Cove, is about a 20 minute drive from the aiport, and to Port Douglas from the airport is about 40 mins.

If you want some where romantic, then I would agree with the above, that Cairns is not the most romantic place as the beach is very bad (marsh-like) and it's very backpacker like, but it's also summer (make sure you slap on SF35+ CONSISTENTLY) so it will be quieter as everyone will be south of Brisbane.

But if you're not too concerned about the romanticness, then I know a couple of places you could stay quite cheap, and offer extremely good value for money. There is this motel (about 4 star motel quality), which is the centre of Cairns, free parking, free breakfast (cereal and toast), small clean swimming pool, free tours around Cairns (they take you on a minibus to natural swimmingholes), selfcatering rooms, free bbq and pancakes once a week and they charge about AU$70-100 a night, and the motel is called Northern Greenhouse. Rooms are basic (with TV), but clean. Also has a cheap onsite bar.

The option is this place called Gilligans, rooms are probably slightly nicer, but more expensive , and without the value (no free breaky, tours, pancakes, bbq, etc), but they have a fantastic pool and bar (the biggest nightclub in Cairns), and best of all anyone can use their pool. I have personally stayed at both places in Cairns multiple times, and have worked at both places.

I lived in Cairns for over a year, and I know it very well (I know all the places the locals go, and avoid), so if you have any questions about it (or Aus in general), private message me.

Also, Tasmania is one of these places that you have to explore, you don't go there to relax in a 5* resort, but Tasmania is beautiful and a great place to visit. I will go again at some point.