Last year used a shuttle bus from Dalaman to Calis think it cost around £9 for 2 maybe less,new bus only 4 stops,as quick as a private transfer, then we caught the Havas bus from Fethiye otogar to the airport 10lira each,took an hour, they drop first at the domestic terminal, then take you round to the international terminal.
I have had a bad experience several years ago when I booked a return shuttle service got to the resort OK but didn't get picked up on the return journey, we were lucky and managed to get a lift from a friend of a friend, so didn't miss our flight.