Used Passat 3C Key Programming (2010)

Hello, unfortunately, I haven't found anything suitable here related to that topic.
We lost our second key for a Passat 3C BlueTDI, manufactured in May 2010, in Switzerland.
A new key costs approximately 140 euros, plus 40 euros for programming.

I read on Google that supposedly only the radio control can be programmed, even with VCDS.
However, the immobilizer function can only be activated by the dealer using the login code.
However, since used ones are available for 50 euros on eBay, the thought of buying one there comes to mind.
It won't work like that because the immobilizer can only be programmed once on the key.
Is this correct?
Can the transponder be replaced?

So, are we going to be nice and bite into the sour apple?

Best regards,

[Translating...]

http://www.passatforum.com/forum/viewtopic.php?f=30&t=22464

So, no.

Thank you very much .