Not trying to be a wise guy, its just that you won't know until you check for the dates/times you need the car. And even then, the results will be true only for the day you checked. The rental companies continuously adjust their rates as the see how many/few cars are rented during a period. In my experience, these fluctuate even more as you get closer to your date.
Fortunately, you can reserve a car now at the best rate you find and then if you see a better one, you can get the lower rate. Kind of puts you in the driver's seat.
Our last trip was a split trip starting on site. I looked (even had a resi) for a car to be picked up at the CCC. We ended up picking a full size from Alamo at the AP when we arrived and keeping it 4 days longer $100 cheaper than a shorter rental on property.
Like the PP said maybe maybe not, but my experience says the AP is cheaper.
BTW, the cost to pick up and drop off at the CCC and pick up at the CCC and drop off at the AP was the same.