Gift-wrapping can often set to a specific price.  The following Prestashop 1.5 tutorial will enable you to set a specific price for gift-wrapping for customer orders.

How to Set the Gift-wrapping Price for Orders in Prestashop 1.5

1. Login to the Administration Panel as an Administrator
2. Hover over the menu bar where it says PREFERENCES, and then click on ORDERS in the drop down menu. Scroll down the list of options and look for GIFT OPTIONS.  In GIFT OPTIONS, select GIFT WRAPPING PRICE as shown below:
   
   
   
   
3. Decide on your GIFT-WRAPPING PRICE and then type it in to the space provided.  Note that this price does not include tax.
4. Select the green SAVE button in the top right hand corner to save the price that you have set.