Hi Siemens Welcome to the forum. :hello2:
Bleeder is right, the malossi will not deliver more torque than the engine is currently capable of but it will change the way it is delivered to the back wheel and make for more sporty performance.
If you search this forum for malossi you will find lots of info and sammy has also just documented his installation experience in the gallery.
As to price, best you google for that. You also need to consider if you are going to fit it yourself - you can judge that by looking at Sammys pics.
I hear what you say about performance mods putting more stress on components - I say this - the Malossi is not creating any extra energy just transferring engine power to the back wheel to a differing performance profile, at worst you are talking a loss of economy and a bit of life out of the belt - but ultimately it depends on how you ride. There are many Burger owners who have done this mod in Europe without problem.
In Sum, it is the only performance mod worth doing on the Burger.