This is an old post from 2010. I cannot be certain of course, but I believe this member may be referring to when Marriott changed their rewards program from a fixed amount of points (for instance 150K points for a 7 night stay at a Cat 7 hotel) to the current program where you stay 4 nights on points and get the 5th night free. Another change made was the addition of a Category 8 hotel. These changes caused stays to cost more points.
I never stay 7 nights in one location, so the buy 4 nights on points, get the 5th night free works for me.