Two weeks ago, I made a reservation at the Seattle Marriott Waterfront using Marriott Rewards. Due to a slight change in plans, I need to extend the stay by one more night. When I attempted to change the current reservation, my total pricing changed from 30,000 points a night to 35,000 for all the nights in the stay. Going back to the reservation website, I noticed that the tier for this hotel had changed from Category 6 to 7.
I can understand that Marriott has the right to change prices and/or tier levels without any prior notification. However, I believe that for a change in reservation, they should honor the original price and only reprice the actual change (ie, additon one night). I ended up making a second reservation just for the added night. This same impact and saved me quite a few points.