Where are/were you? I think you may be looking at the cost of a block of night vs. a single night. In general, if doing consecutive nights on points, the cost per night in respect to points should be lower overall. There are exceptions of course. If you tell me which hotel or property you are refering to, I can get you the answer you are looking for fairly quickly.
Base Points are a factor on the price of the room and your expenditures.
For Full Service and Resorts its 10 points per dollar spent.
If I stay at a property and get a AAA rate of $98/nite one week, but the following week there is no discount rate, and a convention in town so I pay $300/nite, then my points will be vastly different. In addition, I will get 50% for my Platinum status. If I eat my meals in the hotel in a restaurant, or have food delivered and they charge my account, I get points on this as well.
So how much you are spending on a daily or weekly basis, can result in drastically different points earned.
Did you actually have to use that many or was that the number posted on the reservations site? I ran into that same thing for a hotel in NYC last week and everyone thought I was crazy, I think. The next day, the points showed to be the correct amount. I think they often have trouble with their posting amounts on the reservations site. I've run into it several times now. If it seems too outlandish, try checking back later.
I had 2 stays that posted incorrectly, both though with a complicated reservation, as I tried using Points + Cash, but the cash rate is the option for none, and I wanted to use either a AAA or corporate rate which was lower so had to make 2 reservations. When this happens, they record one, and ignore the other.
That is when I called Platinum Support and was surprised to find its a new number with new people