Originally Posted by
Blackcloud
Also full Y is nearly expensive as a D business class fare.
Indeed. I once had a full Y fare WLG-MEL* that cost me NZD40 to upgrade to business class at the airport ticketing counter. The ticketing agents were rather surprised to see someone with an actual full Y fare, and even waived the $100 ticket re-issue fee.
* I don't know why it was full Y - the aircraft was nearly empty; but it was booked by our corporate TA who has a habit of doing weird things. Usually our corporate fares book into K or B, but occasionally Y. We do get a sizeable discount over the list price.