Not so much. In Greece, the crew will be included in your weekly charter fee. Then you have an APA known as Advanced Provision Allowance and VAT, which is the tax.
You will pay a percentage with your final payment, of the charter fee, plus APA, which covers your expenses, i.e., the food, beverages, fuel, and VAT.
The APA amount fluctuates with on the type of yacht you are on, catamaran, motor yacht, monohull. Motor Yachts burn a lot of fuel, their percentage is higher, up to 40%.
Sailing Catamarans typically ask for 20-30% with the final payment. The Yacht Captain will keep an accounting of all costs during the week.
You can view the purchase list anytime. Any leftover APA can be given to the crew as a gratuity or transferred back to you.
We find an itinerary that runs you all over, and heavy alcohol consumption runs up the APA.