in the Wizards menu are beside basic function also some additional functions:

If you go to Wizards menu and click on the Copy Line function, the program will copy the currently selected line. First, select the line to be copied. Next, go to Wizards menu click on the Copy Line function and than Paste Line function. The program will create a new identical line to the original one.
The function is especially useful for compound items to which you would like to change the bill of materials. If you want to add a new line that only differs from the old one in some details, you simply copy the old one and adjust different data.

Step 1: Create a sales order line. Select the desired line, go to Wizards and click on the Copy Line function. 

Step 2: Next, click on the Paste Line function and program will create a new identical line!