A four night stay on points? Really? For that reason alone I'd recommend paying. It pains me to see you giving up your free night!

There are so many considerations you did not share with us that it's impossible to give you meaningful conclusions.

At what rate do you earn points and how often do you vacation using them? There is no reason to hold onto points just for the sake of holding onto points. Marriott can devalue the points tomorrow and you missed your opportunity to maximize their use. Of course, it could happen in the other direction, but an Italian speaking giraffe could knock at your door this evening trying to sell you magazine subscriptions. Anything is possible. Not everything is likely.

Also, the pile of cash would be nothing for Oprah Winfrey or Bill Gates, but would be more significant to a single dad working as a bus driver raising eight kids. While I assume you are neither, we don't know where you are in between.

Assuming you would do another five night vacation in the near future using the points and the money is not an issue, I'd pay $$ for the room. If the points are going to languish in your account doing nothing for you, I'd go ahead and use them. Personally, it would take me four months to earn those points. Last year I used ~400k points on awards travel, but I don't have any big vacations left this year for which points have not already been deducted. Based on that, I'd probably use the points and pocket the money (closer to bus driver than Winfrey/Gates here), but I'd also figure out a way to stay one more night. The next big trip I need points for isn't until June 2016, and I'll have the points needed by then.

Bottom Line: Don't agonize after making your choice. Neither is "right" and neither is "wrong." Both are good for different reasons. You cannot do both.