More information is needed to help you out. Who is changing the amount you are referring to? The airline? Marriott? As I understand the program, Marriott requires a definitive amount of points used to get a specific amount of miles for a particular airline, so I wouldn't think Marriott was changing the amounts. That being said, the airlines have 'peak' and 'non-peak' rewards that require different amounts of miles. Depending on the airline, I have seen rewards on miles for a specific route change on different days for the same route. One day it's peak, the next it's non-peak. I found that one just has to grab it when it is at the lowest amount. I also don't know if the airline will 'hold' a ticket on points until the Marriott points are transferred. You'd have to check with the airline as I'm not sure Marriott would know that answer. Hope this helps.