The economy is cyclical and resale prices will come down during the next downturn, same as the last. That said, the trend line is way up. We paid $84/point for BCV not very long ago. I recently mentioned to DW that we could prob sell it for $120, her response: "Not a chance!" (That she'd be willing to sale.)
I think, economically though, the middle class is being steadily squeezed out. I don't mean just at Disney, but globally. I think Disney's pricing strategy recognizes that. TWDC seems to have adopted a strategy of marketing to higher income clients.
So long as the parks are full this isn't a bad strategy. Add in all the extra events they are charging now, and IF Disney is still in reach of the middle class at all, it's once in a lifetime.
I think that move (catering to a higher income crowd) is what's driving both the new development and DVC pricing. One isn't causing the other, they are both byproducts of Disney's audience reach.
I think you see that everywhere at Disney now - catering to somewhat higher than middle class income. Disney Springs isn't designed for people tapped out to be at Disney at all. No, it's designed to capture more discretionary income for people who have that sort of income.