The major advantage is that the points total at each resort can never go up. They can reallocate points, but that means that if they raise them in one season or for one size villa they have to decrease them somewhere else. That means that the points cost for your
DVC room will not go up over the course of your membership. The same will certainly not be true of resort room prices. Buying a DVC membership is like locking in your future vacations at today's prices, which is fantastic!
Keep in mind that the dues will go up, so it will get slightly more expensive every year. But a 4% increase in dues is nothing compared to a 4% increase in rack rates at the hotel.
I don't know what a hotel room is, but let's guess it's $200/night plus tax, or about $222/night. A Studio during low season and midweek I think is 12 pts/night. If dues are about $4/point, then your dues for that night are $48.
A 4% increase in dues raises the night's lodging to $49.92/night, an increase of $1.92, (or $9.60 more for a 5-night weeknight vacation, while a 4% increase in the hotel rate goes to $238.88/night, an increase of $8.88 or ($44.40 for the 5-nights). Continue that for 10, 15, 20 years, and you'll see that the biggest advantage to owning DVC is it's hedge against inflation.
Of course this is trying to compare apples to apples. Staying weekends, or staying in a 1 or 2-B/R villa, or getting special views, will cost more points so you may not have any monetary savings, but will have better accommodations.
The above of course does not consider the initial purchase. However we purchased in '93 for $57.50/point and I could sell for more than that right now. If instead I had put that money into the stock market, I don't have a clue as to what it would be worth today, but most likely less than I could sell DVC for right now.
Finally, BLT so far has the lowest dues of all DVC resorts.