Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Abilene to McAllen as you normally would.
ABI stands for Abilene Airport, while MFE stands for McAllen Miller Intl Airport. These codes are often called IATA codes, a set of identifiers established by IATA (International Air Transport Association) that is widely used by airlines and the aviation industry.