Laguna 1.8 16v Bj 2000 Disable immobiliser

Hello, I don’t want to bother unnecessarily now, but maybe someone has a tip for me. My son gets his first car from me. I found a great Laguna for little money at 2 years Tüv new brakes and Co.. Everything in best order and everything works as it should. Unfortunately I got only one key to this vehicle and would need a second one. After a visit to the friendly one, they wanted to turn me on a new key for 150-180 euros. the replacement key is just because this one is supposed to be a NOTSCHLÜSSEL, in case my son is the only key there is shot. Remember now to have a replacement key machined by the key man, but he will not help me, because he logically does not have a transponder for the WFS. I would like to switch off the WFS. The vehicle is not “claw-insured” anyway, so this story would not be relevant for insurance purposes. only one tip, what costs such a thing while Freundichen, or someone in the area Heinsberg or Mönchengladbach can help me / wants