Thanks Neil for a most complete answer.
Our HAL cruise was indeed one of those special offers with air included. When we mentioned it to our TA she knew nothing of it and we had to forward to her the Email we rec'd addressed to us.
Obviously there's no hope of any price change even though the cruise appears to have plenty of empty cabins/staterooms still available.
Last January we rec'd a significant reduction in price when a seniors' special was advertized. We did have to move down a deck but we're used to window steerage.
Thanks again for an 'easy to understand' explanation.