Wow! Bro you are super popular sia.
1 'simple' question yet kanne 'arrow'.
Think different car, the air filter is placed differently.
My humble opionion, the labour cost should not cost more than $10 ba.
Believe $5 should be reasonable thou if you are doing standard servicing.
Anything more expensive than that, hhhmmmm believe you can try to lean to Do It Yourself as everyone said here.
Seen a few of your DIY's project here.
So looking at your ability, do not think it will be hard for you to do so, nevertheless it may be troublesome at time to get it done which you may want to pay and get it done.