We have discussed this so many times I thought you would have seen the info and negatives by now. Realize how
DVC and
DCL does this. DCL gives DVC a set price and it's usually a slightly discounted rack rate. DCL can't take the chance that they will gave a great price and that a lot of people will go during times they can sell for more. DCL then must take the points given up and secure a room which they rent through CRO to get the cash to pay DCL. I've always assumed CRO took a cut of those proceeds as well. Since the various dates vary widely in discounted price, DCL doesn't give DVC that much of a break. Expect the cash price through DVC to be far more than the early booking discount prices. For certain weeks and for later in the process, DVC may be cheaper but that is because one has missed the boat on the early booking discounts, not because DVC is a good deal.
You're best deal will be to book early, at least 12-15 months out when possible. If you want to "use" the points, renting them is the best. When you decide when and what cabin types you're interested in, you can then get prices and points and compare directly to make a final decision.
There are negatives for doing this through points other than the "cost" comparisons. With cash you don't pay until the last 2-3 months other than the deposit and can cancel without penalty until the final payment date. With points, you pay any cash amounts in full up front and if you cancel, there are substantial penalties no matter how early you cancel.