Shadus, I had in fact did some very vague planning for a roadtrip in WA (Western Australia). So I asked a friend who'd studied in Perth for many many years. Just before she came to work in Singapore 1 month ago, she emailed me the following information... Really useful information in my opinion... She's fantastic and i love her so much for it!
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1. Best time to come.
I think you should come around September to October. Although Manta rays breeding season is around july-aug, you can still see lots of them during sept-oct while not missing out on the greenery of 'land' nature because it would be spring. Whale sharks are I think all-year-round. During spring time, the land won't be so 'dead' and dry if you know what i mean.
2. Car rental
I have rented a campervan before. I think it would be very convenient to have a campervan when you travel upnorth so that you can camp in the beautiful national parks. Make sure you choose the 4WD ones, coz some national parks are only accessible with 4WD. For some ideas on the rates, visit
www.britz.com.au They are not necessary the cheapest one, but just have a look and you can do rough costing.
However, one bad thing is that. You know how you may be staying in a town for a couple of days. Let say you chose the campervan that needs to set up tent. You will find it a hassle if you need to dismantle them just because you need to use the car to get somewhere around the town. So make sure you take that into consideration. I wouls suggest you pick something like 'The Bushcamper 4WD' if you look at the website.
Campervans might be good for roadtrip but it wouldn't when you want to stay in perth. I am not sure but I can't remember if there's any caravan park in the city. The closest I know is about at least 25-30 mins drive. So if you are staying in the city, I suggest drop the campervan. A little scooter would be a great mode of transport and there are alot of backpackers' lodge in the city.
3. Petrol Price
It's been fluctuating but settling around $1.13/lt. You will have to check again as you know the prices have been very inconsistent. Visit
http://www.fuelwatch.wa.gov.au/ for latest update. Notice that prices in metro areas are different to regionals.
4. Accommodation
Backpackers here are rather cheap. They cost about $15-$30 a bed a night depending on location, season and type of room. There are rooms that you share with 7 other people, then there are also singles. So prices may vary quite differently from places to places. But if you are renting caravan, then you would need to pay caravan park fees. They can be as low as $8/night per bay to $25. Price varies according to the facilities the park provides (like powered or non-powered), water, common kitchen, bathroom, etc. Of course, locations would affect prices as well.
5. Cost of living
Cooked food (from restaurants, stalls.. etc) are generally a lot more expensive compared to cooking your own meals. Simple meals like sandwiches, frozen meals and salad would proably cost around $3-5. It's considered cheap here as a McDonald value meal cost around $6 (just to give you some indication).
6. Other costs (that I think you need to take into account)
You may need to think about National park fees. They don't cost alot, probably about $10-$20. Some charge per person, others charge per vehicle. Other costs would probably include boat charges (for snorkelling trips) and gear hire (if you need).
7. Useful information
You can find lots of information through these websites. You can use these links for ideas but I do not recommend you to directly book any accommodation, car rentals and tours from them. From my experience, going through travel agents are normally cheaper than calling them direct. If you need to book anything, let me know as I know a travel agent friend (and she always give me good deals) =)
http://www.westernaustralia.com/en/
Check out this web for ideas on drive itinerary:
http://www.discoverwest.com.au/mapall.html
Ok. I think that's quite alot of information for now. Hehe.. let me know if you need more information. More than happy to help. =)
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Let me know if you have anymore enquiries.