Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Singapore to Charleston, West Virginia as you normally would.
If you book a flight to Charleston from Singapore, you will be flying to Yeager, which is the city’s only airport. Charleston Yeager (CRW) is located 4.3 km from the centre of Charleston.
These are just IATA (International Air Transport Association) codes. They are used in aviation to identify and differentiate airports. That’s why a Singapore Changi Airport to Charleston Yeager Airport flight would often be abbreviated as a SIN to CRW flight.