Due to multiple factors, expect to potentially pay more when booking in December. For low rates, May can be a great choice for travel to Nevada. Flights to Nevada from Melbourne Avalon Airport in May are about $1,214 on average during May, but can be found for as low as $902.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Melbourne Avalon Airport to Nevada as you normally would.