I'm sure Jim didn't mean to be harsh, just honest
OP, Actually it is pretty far off base as I'm sure you're figuring out by now. I see several incorrect assumptions, these include that resale prices track retail and that market forces are broad enough to give a true value on the open market. Regardless, the market is as you see it, maybe a little over half of what you paid. Plus, if all of your contracts were financed, they likely were financed as a unit meaning it's unlikely you could sell one or two without paying off the remaining ones.
Your situation is one of a number of reasons why I try to press those looking to buy to make sure they understand the risks and negatives, to never finance and to not overbuy the number of points they truly need or the higher cost resort. I can't tell you what to do but for most people in this situation I think the first question is whether they can afford
DVC (or even Disney) at all. Truthfully if $1800 a year gets one into trouble, the answer is likely no. For most the best decision is likely to sell all, pay the upside down amount and start saving for when they really can afford it so it'll be a blessing and not a curse. Let us know how it works out and what you end up finding out along the way, esp how it works with trying to sell part with a loan in place.