It's really nor worth bidding up to Business Class on AZ's shorthaul aircraft. And based on your itinerary, you only seem to have 90 minutes between flights, which involves leaving the Schengen zone, so it's not as if you will even really get to benefit from the lounge during your transfer.

However, if you feel you must, then stick to the golden rule of bidding on any auction - decide yourself, objectively, how much you are willing to gamble, and then make that offer.

But, again, I would instead recommend you keep your money for Zurich - a VERY expensive city, especially in comparison to Cairo!