If you are going to buy teamviewer, think twice! I will explain you how they owned me and maybe save yourself a disappointment.
They allure you with a free for personal use, almost full featured version, which works indeed very well: set up is easy, remote connections are quick, sessions are stable and the video stream is fast with any decent internet connection.
They propose you a pay-once license starting from € 500 (minus 1€) and up to € 2.000 (minus 1€), saying that they will grant you at last 10 years of operativity.