Go through your results for flights to Karratha in Australia with Netflights. Although Qantas usually has the best prices, it's best to double check what's available for your travel dates.
Flexible on dates? Conducting your search by month allows you to compare prices to Karratha throughout the year. Accommodation prices will also be higher at this time of year.
Look out for flights with Qantas, as they often have good deals. Or broaden your search by looking at other airports in Australia.
Looking at a few different departure airports will give you even more choice. See what you can find. And remember, it's best to book your flights in advance wherever possible.