People have answered your finanace questions, but please do some research into DVC before you buy. Your statement above shows that you do not have a good grasp of how DVC is set up. You do not purchase in "the off season". With DVC you do not purchase a set time. You also do not purchase "weeks"
When you purchase DVC, you purchase points - a 100 point contract, a 160 point contract, etc, you get than many points per year. Those points are used to reserve rooms. Rooms "cost" various amount of points, based on the size of the room, the time of the year, and the particular resort. The point "cost" for a given room can change from year to year (but that does not happen much, and only by a few points). You get your point allottment every year, but you can bank or borrow points in a limited fashion. You are also not gaurenteed a room at given time of the year (with a few exceptions, but not at BCV) . It is first come first served. You get to book 11 months out at your home resort (where you own) and 7 months out at other resorts. IF you decide to try and book a room at the last minute, there may be nothing available.
IF all of the above works for you, then that is great. I own DVC and am very happy with it. But you need to haev a clear understanding of how the DVC timeshare system works, and if it works for you.
-dave