Actually AWS RDS offers High Availability[1] at a higher price from their single AZ deployments. I've been using it for quite awhile with no issues so far. Compose looks much more expensive than RDS with multi-AZ.
[1] http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Concep...
It would roughly compare to AWS RDS (just that you can't) kill the instance after a half month and only pay half the month. Then AWS would've been on 15 USD ~ 13 Euro with 1 GB Memory and 16 GB Disk, compared to: paasdb-1g that's a lot more, but RDS is really solid even on a Single Node, so it's hard to say if you get the same quality for just 6 Euro. It could be true, but it doesn't need to be true.