iTunes synchronize all ipad applications

You only will be charged if you use the same iTunes account. The iPad is simply not very well to tell you that you already have the app until you press the button "buy". Rest assured it that always with then returned a message that says you have already purchased it and no charge.

But until you do, receive you an error in iTunes? When you connect your iPad and select in iTunes, change to the "applications" tab (3rd in the list), you have all the applications you want to be installed ticked in the column of apps? If they are checked and they are unable to install when your press "synchronize", you must obtain an error in iTunes tell you why. If so, what is the error?