I would suggest that you call Disney, get an information packet -and go to a presentation if possible. Then you can crunch the numbers, ask questions here, and of your DVC 'guide', to come up with a decision that is right for you.
Even if you are planning on buying resale, it is still a good idea to go to a presentation. If you have heard the horror stories of other timeshare presentations, don't worry, DVC is REALLY no-pressure.
If you do decide to buy, the best suggestion we would make is - buy where you want to stay. As an example, we own at BWV and our favorite time is early December. This is a VERY popular time among members and does book up quickly. Making our ressies 11 months in advance isn't a problem for us - more anticipation of our next visit 'home'. However, if you would like to vacation then and are more of a last-minute planner type, or own elsewhere and are hoping to get space at the 7-month window, you could have a lot of difficulty getting in at BWV.
If you are planning on buying with the intent of only occasionally staying in a DVC resort and mainly trading elsewhere, another timeshare would probably make more sense $$ wise. From what We've seen on the re-sale sites, DVC has certainly held its value (we can sell for more than what we paid). The DVC annual fees don't appear to be out of line with other 'high end' timeshares (Marriott). While I don't know anything about them, there are PLENTY of other timeshares for sale at prices that appear to pennies on the dollar of what the original buyers paid. There appears to be something for everyone. That said, we believe you get what you pay for and we've been very happy with DVC.
Good luck with your decision.