I am unable to find the NCL list from my cruise last week but I have the one from my HAL cruise 5/2/10.
This is regular service for dry cleaning.
Item - Press only - Clean & Press
2 pcs suit - $5.50 - $9.00
Tuxedo - $6.00 - $9.50
Tie - $2.00 - $3.00
Dress Formal - $6.50 - $10.50
Shirt/Blouse - $3.50 - $5.00
This should give you a rough idea, I assume NCL would be close.