The difference in price is due to the fabric the paddling suit is made from, and the neoprene neck, not in the design or cut of the suit. The Kokatat Super Nova paddling suits are made from Tropos T3 material, not Gore Tex. Tropos T3 is a breathable, waterproof fabric that works great, but isn't as breathable as GoreTex. I had a Super Nova for one season and it was a really nice option for rafters who can't afford/don't want/don't feel they need a full latex gasket drysuit. I found that mine wasn't seeing as much use as I thought it would and I needed new oars, so I sold it. A gal in Canada who does a lot of 3 season sea kayaking bought it and loves it.
The claim is that the neoprene neck (the wrists are latex gaskets) in the paddling suit will allow a small amount of water entry in a swim. I never swam in mine, so I can't say. I believe Alex aka Kazak4X4 and his wife use them, and like them. If I ever needed a dry suit in the future, I'd definitely get a Super Nova again.
PS - I just realized that Kokatat does sell a Goretex suit with a neoprene neck, so maybe that's what you have???? That seems like the best of both worlds to me. Good luck finding your suit a new home. Any Kokatat suit is a great investment.
"We are all visitors to this time, this place. We are just passing through. Our purpose here is to observe, to learn, to grow, to love....and then we return home."
Australian Aboriginal Proverb