Someone help me figure out where my math is wrong. If I want to try and take advantage of the Flight + Nights Marriott package and want the option of a category 9 property that would cost me 390kMR or 130kspg now. I would need 96k SPG to get 120k airlines miles at the 1.25 rate (though I know I would have to actually transfer 100k for 125k miles), which means that I would be paying 34k SPG for a 7 night certificate in a category 9 hotel. 34k spg translates to 102k Marriott, meaning I would be paying 102k Marriott for 7 nights in a category 9 hotel or 17k Marriott points per night w/ 6th night free. My math is off here, right? That seems way too low.
I am also curious how the certs will shake out come August. Will category 9 certs be good for category 7's? Will it move to category 6 since that is where 45k points will sit in 2019? In the August-Dec 2018 span, would I be shooting myself in the foot for having points locked in a cat 6 hotel reso when 7's could be booked for 60k/night?