Mark,
I built an 8x16' floating deck from 2x12 and 2x6 PT lumber for ~$400. I used blue poly 55gal drums that I got free, but they hardly show. I wonder if the ice up in Dayton (my old home town) would demolish a floating deck or a stationary deck faster?
Let me know if you would like some building instructions. They're very simple, and we absolutely love our little deck.