When Marriott announced their award category changes that go into effect March 5, I noted that 346 hotels would cost more points and 37 would cost fewer.
I initially wrote that you could use points advance to lock in reservations now at the current rate even if you don’t have the points, and redeem later (after March 5 when prices go up). Several readers pointed out to me that Marriott implied in their announcement that this wasn’t the case. However I’ve re-confirmed this still works.