Okay, guys, thanks for Your inputs, I have to react.
First, I know, reading of an advertisement is always irksome.
In this case, it is not "selling" in exact words. It is much more sharing informations.
Those ugly thirteen dollars are some, say, protection fee, to filter all those interested, and can not cover all the effort ever.
I am ready for DISCUSSING about the landing gears, not for selling CD´s.
Best
Tom