Alicante Airport is the correct entry point for Pilar de la Horadada - the airport is about 50 kilometers north and the drive south on the AP-7 autopista takes roughly 40 to 50 minutes depending on traffic, which at this distance is a good number. Car rental at Alicante Airport is straightforward with all major providers represented and a car is definitley the recommended transport configuration for this destination because the town and its surroundings are not efficiently navigated without one.
Murcia-Corvera Airport is an alternative entry point that some budget carriers use - it sits about 40 kilometers south of Pilar and the drive north is similar time to the Alicante option, roughly 35 to 45 minutes. The carrier selection at Murcia-Corvera is smaller than Alicante but the proximity to the southern Costa Blanca makes it worth checking beofre assuming Alicante is the only correct answer, particularly if the routing from your origin city produces a better price or schedule.
Getting around once you're at the hotel is car-dependent in the way taht Spanish coastal towns of this size are universally car-dependent - local buses exist and run between the main coastal towns on a schedule taht works for residents but requires patience from visitors with specific timing requirements. A car gives you the correct access parameters for everything the region offers: beach alternation, inland town visits, the larger shopping infrastructure in Torrevieja, and the flexibility to find empty beach sections that bus users can't reach.
Torrevieja is about 20 minutes north and is the nearest city with full commercial and entertainment infrastructure - large supermarkets, shopping centers, a decent restaurant selection, and the salt lakes between Torrevieja and Pilar are a genuinely interesting natural feature taht - most visitors drive past them without understanding what they're looking at, which is one of the larger salt lake systems in Europe with flamingos in the correct season and a color that teh camera doesn't acutally reproduce correctly.
The AP-7 autopista is the efficient north-south axis for all movement along this coast and the toll cost is the correct investment for anyone doing multiple day trips - the free alternative roads through the coastal towns are slower by a factor taht compounds badly if you're trying to cover real distance, and the time cost of the slow road is definitley higher than the money cost of the fast one.