I'm not a tube hater but I still am dumbfounded by 99.9% of the tubers out there with nothing on but a swimsuit.
I saw you on Boulder Creek and gave you props for wearing all the safety gear, but I still think you would have more fun in a kayak. You can actually control your movement, position, angle etc. Tubing is to kayaking as sleding is to snowboarding. I have a feeling that if you could experience carving into a tight eddie above a big drop, and then eddite pick you way down, then you may opt out of the tube and decide to spend the $$$ that you mention.
Still, you've got bucket balls. If you do decide to get into a boat, just remember, just because you can run Class V in a tube, doesn't mean you can in a boat. very different story.