It depends on your travel dates and your flexibility.
Would you be really upset not getting BWV during food and wine? Or getting BRV during Christmas?
Then buy where you want to stay.
Would you like to visit all resorts and can visit during the summer or other slow
DVC periods? Then buy a resort you don't mind staying and try at 7 resorts. I've stayed at all resorts except WL (targeting it for next time) switching at 7 months, but I've also been "stuck" at SSR points at times (and enjoying the stay).