Its not really worth calculating. Long term, maintenance fees are the primary cost. Buy in is just a smaller piece of the pie.
Without knowing what the rate hike will be, it is next to impossible to guess what the long term costs will be.
Even when you factor in precise inflation rates etc, the fee bump does not always follow that trend.
For example. If you bought a 200 point contract at Animal Kingdom today for $125 per point, and held it until 2057, the buy in would be $25000 without closing costs .
Long term cost per year will vary from $4450 ($1620 in todays dollars) per year to $6350 ($2325 in todays dollars) per year depending on if the maintenance fees stay at a 4% increase per year average, or creep up to 6% increase per year average.
Long term total cost at 4% average fee increase per year is $155712 ($57000 in todays dollars). Long term total cost at 6% average fee increase per year is $222285 ($81370 in todays dollars).
We bought because we love 1 bedrooms and love the location (we stay primarily at VGC). It is true that we stay in much nicer accomodations, but we still spend more now that we would if we hadn't bought into
DVC. It is still worth every penny.