BLT is difficult to get right now, but don't forget that it's a pretty large resort and nowhere near sold out yet. That means that the resort has a lot of capacity, but much of it is not yet in the
DVC points inventory because it's unsold.
As time goes by, two things will happen. One is the initial excitement will have subsided and people will look twice at the higher points costs of staying at BLT. The other is that much more availability will be in the DVC points inventory. Less demand, more supply = easier to book.
If you just
must stay at BLT (AND can book your vacations in the 11-7 booking window), or you
must be able to get MK view (and can book at 11 months), then buy BLT.
The same math goes into AKV. If you
must be able to get specific accommodations at AKV (in the 11 month window), then buy AKV.
If you'd just like to stay at those resorts when you can get them, or if you can't reliably expect to book more than 7 months in advance, I'd look at both OKW or SSR via resale.
Another factor is how many points you plan to buy. If you are going to buy a bunch of points, then the $30+ per point price difference between direct and OKW resale becomes more important. If you only want 50 more, it's still a big difference, but the overall resale savings would not be as great when you factor in closing costs.