From our personal experience, it depends on the current incentives and available properties. When we purchased, we did so outright from Disney- Bay Lake Tower with an incentive of a 4 night cruise. We are big-time number crunchers and this was, by far, the best way to purchase at the time we did. And with the other properties going "down in value" (I say that loosly, as a few, have only gone through a few of their years of use and already resell WAY below their original starting price) vs some that have gone up (Beach Club, for example, was sold for something like $55 a point at the beginning of DVC, and it sells on the resale for $80-ish a point with only 31 years (give or take a year) left on the contract). We felt that BLT would follow suit, and thus far, it has.
We are currently looking for a 2nd contract, and this time we're looking at resale, simply because we don't need another BLT contract, and would like to purchase something we know we'll use now, but may dump 10 years or so down the road, depending on how we use it then. For this reason, we're looking at SS, as the price per point per year left on the life of the contract is lower (with the addition of reasonable maintenance fees).
Hope that helps a bit. Honestly, it really depends on you, what you want, and what you feel comfortable purchasing for your use.
