The key state in your scenario is the date the appraiser notified you of the increased cost or that the appraisal will be of Property Type B instead of Property Type A and you should be aware that means a changed cost. And "you" means the bank, whether the person notified is in your processing area or the lending officer, etc.
John S. Burnett
Fighting for Compliance since 1976
Bankers' Threads User #8