Do you have a place to store a regular boat? If not, I can understand the inflatable. I have picked up 3 canoes off of craigslist for $75 or less. The last was an aluminum 17ft that I still have, which I paid $50 for. None of them needed much work, if any. People were just needing to get rid of them for space.
Personally, them only inflatable I liked was a kayak. I have had a few of the boats you described, not the exact ones, but I did not have good luck with them. A little bit of wind, and I was blown to the other side of the lake.