Flights from HCM to Hanoi

Book your flights once you're here and you have confirmed dates. The cheap (discounted) tickets usually don't give you an option of changing flight dates.
You can compare fares from Vietjet and JetStar sites.

"Is it cheaper to purchase the tickets in Vietnam or pre-book them here in Australia?"
=>No, as long as you make sure the date & time of flight, you can book and payment directly on their site with visa or kind of online method, they apply the same price at the same time everywhere you book online.
And domestic airline has Vietnam Airline, Jestar, Vietjet air. Jestar+Vietjet is cheaper, it delays sometimes so don't plan anything too near with time of Flight

Flight search engines like https://global.momondo.com will find the cheapest flights wherever you are.

Thanks for the replies, I will know my dates by this coming weekend so I will have a good look then.

Andy Passenger wrote:

Flight search engines like https://global.momondo.com will find the cheapest flights wherever you are.

I just used that link to search flights from Hanoi to Danang on a date in October. The lowest price available in economy was $41 USD.

I then searched the same date on the Vietnam Airlines site.

I got multiple flights for $36 USD

OceanBeach92107 wrote:

Andy Passenger wrote:

Flight search engines like https://global.momondo.com will find the cheapest flights wherever you are.

I just used that link to search flights from Hanoi to Danang on a date in October. The lowest price available in economy was $41 USD.

I then searched the same date on the Vietnam Airlines site.

I got multiple flights for $36 USD

I always use Momondo to find out which flights are available at which time. Then I first check directly with the airlines and book there if it is not more expensive.
But at Momondo (or other flight search sites) are also listed round-trip or multi-city flights which consider different airlines for the individual flights. In this case it is more easily to book the flights listed at Momondo direct via eDreams, for example.

It is anyway advantageous to check with the airlines themselves, as the baggage arrangements are very different.
E.g. you will find a cheap flight at AirAsia, but have to pay almost the same amount onece more for a checked-in suitcase. Then you can just as well book e.g. a Vietnam Airlines flight where 32 kg of checked-in luggage is included.