VGC is a very small property with only 48 total DVC villas (23 - dedicated 2 bedrooms, 23 2 bedroom lock offs (which can be broken up into a studio and 1 bedroom), and 2 grand villas). It is very hard to get in at 7 months (even at 10-11 months out there are often dates already completely booked). And the selling price through DVC for VGC is over $300 (although it is not for sale at the moment at all and has a closed waiting list to purchase). This is all to give background on why the resale price is over $300. Most who own at VGC use those points at VGC as Exclusive Use Points (EUP).
Adding DLT may ease some of the CA booking issues (questionable to me). But that will only be booking at DLT, VGC will continue to be hard. My VGC points will continue to only be for VGC. I will probably also buy some DLT points to have for Exclusive Use at DLT at the 11 month mark. And I suspect many others who want DLT will be the same.
Adding 5 new resorts will not ease the VGC (& DLT) situation. That is the only game in CA. And those people will not be booking out to WDW resorts or Aulani as frequently as WDW will be trying to book in. If you want VGC, you need to purchase VGC. And right now that market is around $275-300 per point. If I was to sell my VGC points (not happening for anything though), it would be listed at over $300 and I would take no lower than $295 (I have small contracts).