As I was researching before buying into
DVC, I created one heck of a spreadsheet and was analyzing so many things.
My analysis clearly showed that over the years, the cost of annual dues becomes the dominant overall cost.
Maybe I missed some of the posts in here, but besides expiration dates, an important thing to look at when comparing resorts is the
points charts, and how many points it would cost during a season you're likely to visit in the studio/1br/2br/etc that you'd like to get. The older resorts typically have lower points/night and the newer resorts typically have higher points/night.
If you really want to stretch how far your $ goes, and are flexible to book at the 7 month mark, you may want to buy BLT or VGF and book stays at OKW. Buying BLT or VGF because they tend to hold their value on the resale market pretty well, and they have some of the lowest annual dues $/point. Booking OKW because the points/night are some of the lowest around.
But that is overanalyzing things purely from a numbers perspective. There are so many intangibles this doesn't capture at all. For example, if you're staying at BLT, you can walk to MK in less time than it takes the bus to make the loop at all the OKW bus stops. Similar for staying at RIV and riding the Skyliner to DHS or EPCOT. Or being able to watch the animals from AKL, etc. Lots of locations, theming, room configurations, transportation, etc, to consider at the various resorts.