You can buy direct through Dis for the older resorts, they just won't advertise it. You may have to wait for certain UYs, though.
As for buying resale versus direct, we had gone on the tour and decided to buy and got our paperwork through the mail. After I did some research, we could get a better deal on what we were looking for via resale. Look at the ROFR thread, see what BCV/BWV points are going for and run the numbers for yourself. We've purchased 3 contracts and have had no problems. It just takes 2 - 2 1/2 months from start to finish, and you can't book your vacations until you close and your in Dis's system. If you're in no hurry, it can definitely save you some money.
If you're worried about how you'll be treated if you buy resale, don't. My BIL/SIL bought direct, and we are treated exactly the same by Member Services. I even compared a call that she and I made separately regarding reservations for spring break. We were given the exact same information, both waitlisted for the same request, and both had our waitlist come through within a day or two of each other.
Lastly, we haven't had problems booking where we want to stay, but if you're heart is set on mostly staying at BWV or BCV, buy where you want to stay. That's especially true for BCV since it's one of the smallest (if not the smallest)
DVC resort.
Good luck on your decision!!!
