Due to multiple factors, expect to potentially pay more when booking in December. For low rates, September can be a great choice for travel to Bangkok. Flights to Bangkok from Myrtle Beach in September are about $1,267 on average during September, but can be found for as low as $997.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Myrtle Beach to Bangkok as you normally would.