they will change only one coil for you no matter how much you pa

if you know which coil needs to be changed, you can buy one and change it by yourself. there is only one (or two) screw, and you need a screwdriver. you do need to change the 6 spark plugs. it is so easy to do the work. if you ask them to do it for you, you need to pay for the 6 coils, even though they change only one, as you can't know how many they changed anyway.