EC2 snapshots vs. bundled instances

It's my understanding that EC2 snapshots are incremental in nature, so snapshot B contains only the difference between itself and snapshot A. Then if you delete snapshot A, the difference is allocated to snapshot B in Amazon S3 so that you have a complete snapshot. This also leads me to believe that it isn't prohibitively expensive to have daily snapshots A-Z for example, that it in storage cost it is basically the same as one snapshot.

What I really want is to back up my snapshots to a bucket in Amazon S3, so that if an entire EC2 region is having开发者_如何学运维 some problems --ahem cough, cough-- the snapshot can be moved into another region and launched as a backup instance in a new region.

However, it seems you can only bundle an instance and then upload a bundled instance to S3, not a snapshot.

The bundle is the entire instance correct? If this is the case then are historical bundled instances significantly more costly in practice than snapshots?

I use an instance store AMI and store my changing data on EBS volumes using the XFS filesystem. This means I can freeze the filesystems, create a snapshot and unfreeze them.

My volumes are 1GB (although mostly empty) and the storage cost is minuscule.

I don't know how an EBS backed AMI would work with this but I can't see why it would be any different. Note, however,that you need to bundle an instance in order to start it. Perhaps you could just snapshot everything as a backup and only bundle them when required.