You will eventually be able to find lots of 05-06 997/S cars that are used. I bet the vast majority of them have been driven in a mostly responsible way. I.e.owners obeyed break in, got them serviced, didn't ream the cr*p out of them on a routine basis.
Say you find a non-demo with the same low mileage down the road, with same depreciation, you may have more choices for options/colors etc, it might be a better bet?
I think your dealer can do a nationwide used-porsche car search for you, right?
You got the cash and, compared to ordering a new car, the pre-owned market has got to be a BIG buyers market. I'm just guessing though.