You won't get anything near what you paid. You should use your SO's to go elsewhere, when you cannot go to Kauai. The best way to get value is in using what you own, not selling your week for much less than you paid.
I have found the best revenge is in buying resale. So selling through the resale market doesn't seem logical to me.
40 years ago we bought our first timeshare, couldn't afford it, shouldn't have bought it, but we still own at that resort (but better weeks), and it was ridiculously expensive back then for an early summer week. But we saw it as an investment in our family. It's such an ordinary timeshare, no real amenities, just a nice mountain condo, 3 bedroom, 2 bathroom. It just appealed to us at the time. We paid about $7,000 for it 40 years ago. That was a crazy amount of money back then. We could have bought a very nice car. So regrets, I have a few (Frank Sinatra is singing in my ear right now), but it all turned out okay.
About two years after buying our first, we bought a second from the developer. That has turned out well, but once again, we regretted our decision. Two retail/developer purchases later, we are glad we did it. Sure, I would like to have rescinded, but now we own 7 weeks at our second timeshare resort, also in the mountains. We own four ski and 3 summer weeks. We rent the ski (unless our kids decide to use them) and trade the other three weeks for great destinations.