I have posted this question on boardgamegeek too, but I really need an answer

Last night we played this game once again and had a discussion about the bid value of the Draco and Zeppelin cards.
In my opinion their bid value is always 2 or 5 wether they are used for flying or as a bonus card.
Others said it was only 1 for flying because of the fact there is no number on the fly symbol on the cards.

In my opinion this would be nonsens because then you would have to pay 1 or 3 gold for the same action (flying) and other players could easily overbid you.
And reading the rules I am convinced I am right

So what is the truth here ?


Great game btw !!