How important is where you stay to your group? For some, like me, its a big priority and I own at both BLT and BWV because that is where I want to stay each and every trip.
I spent more for BLT so that I could book it without worry. I ended up getting BWV at a great price last year--$55/pt--so that was a bonus in terms of choice.
If you will be disappointed in staying at SSR, then IMO, don't buy there. If, however, you would be okay if, for some reason, you can't trade out at 7 months, then looking for the best deal--buy in cost and MF's--is a great strategy.
There are very few times of the year and a few options that will be difficult to get at 7 months. For example, getting SV at BLT is difficult if not an owner--so is concierge at AKV and SV rooms at BWV--VWL during December of the Epcot resorts at BCV/BWV are also difficult during Food and Wine...
Nothing is impossible to get so I think it really depends on your comfort.. When you buy
DVC, at the end of the day, you are buying the right to stay at your home resort only so you really need to be comfortable with that..