Timing belts

Hello, was today at the “Friendly” to have the service done: Now he told me that I should also have the timing belt changed although I do not have to change the timing belt yet! Since the 180hp TT of the timing belt has to be changed after 5 years and here is no difference with the 180hp and 225hp TT. Should I now save the 500€ and leave the old timing belt inside and possibly risk an engine damage or yet change now? What did you do? (according to “elsa” or how the computer system at the Audi dealer is called I have to change the timing belt only in 2010 !)