No, you write a script that runs the sync and shut down the instance. When for instance is stopped you don’t pay for it. Resuming it is a simple api call. You don’t even really need to do the sync, it’s just to be certain if the instance volume is lost you have a backup.
The shutdown / stop on an instance is like closing the lid on your laptop. When you start it again it resumes where it was left off. In the mean time the instance doesn’t occupy a VM.
A caveat is you can’t really do this with spot instances. You would need to do a sync and rebuild on start. But, again, scriptable easily.
For home computer setups, you can simply walk away when you need a break.