From Malaga Airport to Nerja it is about 50 km and a taxi should cost around 65-70 euro. It is advised is to pre book taxi prior arrival. A budget alternative would be to take the train from the airport to Malaga Maria Zambrano Station (10 min ride). Here you would walk to the main bus station (takes less than 5 minutes) and take the bus to Nerja. The direct bus takes about one hour and the one that stops in multiple villages on the way takes about 1h 30 min. In total the costs would be around 7-8 euros from the Airport to Nerja.