There are some really good deals in the buzz classifieds right now; but I guess you're not in CO yet. Remix 69 for example.
Probably the biggest issue with the Comet, in terms of getting on easy whitewater, is that recreational kayaks are hard to roll, because they are so wide. I haven't tried actually; can you roll it? You can probably sell it for more than 50% of what you paid, and as you said, you've "had fun with it", and that is what its all about!
If you can find a roll class in a local swimming pool this winter, do it. They might have boats you could borrow. You could learn to roll in just about any old whitewater boat you can get your hands on; or a longer, narrower touring kayak.