To put some raw numbers into view for you, I bought SVV-Bella last year. Deeded, Mandatory. this means you get (in my opinion) the most important perk of retail, VSN Access. You can star options (SO) trade to other resorts. Without sharing too much financial detail, I paid roughly 1000 + closing for a unit that netted me 97,500 SO every other year. Some may even say I overpaid for that value. 20k is far too much....
That said, with Abound coming out there are two schools of thought, resale purchases could be a lot more valuable (very unlikely) or resale purchases could be a less valuable (I think likely), third option is no change in value I guess. Point is, we know pretty much nothing about how Abound will affect resale. If you want to SO trade, Id recommend waiting to see some details in writing before making a purchase. If you're looking to spend your time at SVV, then there's really no harm in making the purchase I don't think.