Hi, intending to book a first trip from Hanoi to HCMC over 2 weeks in April stopping in Hoi An. Keen to do an overnight train Hanoi to Hoi An but for the second leg wanting to book a domestic flight. Trying to find flights but only seem to see Vietnam airlines on offer and quite expensive. How far in advance do Vietair or Jetstar offer cheap flights and is it worth waiting given they likely charge for baggage allowance rather than include in the ticket price. Any help appreciated.