Jen
Apologies, I meant to answer your question. Two weeks in a Studio at SSR would cost you 246 points for the first half of August, 224 for the second half, and 235 if you straddled the middle two weeks. If you're saying that you will always want to go for 2 weeks in August (or at least for the foreseeable future), then it's going to cost you around £11000.
The thing to remember, is that the points can't ever increase. Disney can move them around, for example, Easter is one of their busiest times, so that will always fall in the Premier category (the most expensive), even though the dates change year on year. However, the overall points for a resort can't alter, so other dates will then move into a cheaper category to accommodate this change. Even though £11000 is a big initial outlay, you will probably break even within about 5 years, giving you another 40+ of free holidays! Of course, you have to pay your annual dues, but there are restrictions on these. Disney isn't permitted to make a profit - dues just cover the cost of running and maintaining the resort - and it's in their interests to keep them low in order to keep DVC attractive to purchasers. If you assume that dues will rise at the same rate as the rack rate of the rooms (i.e. the cost to the general public of staying at a DVC resort), you really can't lose.