If I read correctly, it is pretty expensive. $0.10 / connection (peer) / hour, plus dynamodb and transactor instance charges. For 100 clients, and not including the dynamodb or transactor instance(s), this makes it a hair more per year then a quad core oracle instance.
The $0.10 price tag is for the transactor, which just ensures that writes are atomic (but doesn't do any writing itself). I guess we'll need to do some benchmarking, but I suspect that $0.10 per peer per hour won't be as expensive as it first seems.
