Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Bahrain to Haiti as you normally would.
Great question - BAH to PAP just means Manama Bahrain Intl Airport to Port Au Prince Mais Gate Airport. Now you’ll know what these unique codes when you look for flights! Cap Haitien Airport (CAP) are other airports near this flight route and their unique identifiers/IATA codes.