I would think that just for the extra points, it would be worth 1 more night.

$100 spent for a 1 night stay will give you 6500 points as concierge. Gold will net you 5000. 1500 diff x 75 nights will get you 112,500 extra points. Assuming all your stays are for 1 night each, and the numbers may chanage if you stay more than 1 night per stay, but still worth 1 more night.

Not even taking into account anything spent on food and beverage, which will give you more extra points.

Go for it