Can I pay the $40 at the gate and upgrade to boarding positions A1-A15, if I have not paid for Early bird boarding when I booked my flight? Let's say my boarding position is C50 (becuase I did not pay for early bird). I can then upgrade to A1-A15 by paying the $40 at the gate? Thanks for your help.
In short, yes. (Generally those who have purchased EarlyBird don't purchase upgraded boarding at the airport because you don't need both, but you still can). If there are any boarding positions available between A1 and A15 then you will be able to purchase upgraded boarding at the airport; you don't have to first purchase EarlyBird to be able to purchase upgraded boarding.