getting your hair done for formal nights is very popular on cruise ships.
Go to the salon right away after you board to make your appointment.
Price depends upon what you have done. The more complex the do the more it will cost. I have chin lenght hair and for me to have a wash, dry and style with curling iron & fancy clip(brought my own) cost $35.00 w/tip.
When you book your appointment have a good idea of what you want, so that you can be matched up with a stylist who will give you what you want. Some specialize in updo's some specialize in french braids etc, etc.
If you want a fancy clip/barette- bring your own or be prepared to pay $$ for it.