I know that a snapshot costs $0.05/GB monthly, but that cost is full charged when the snapshot is created or it will be per hour like others services?

Just to explain, let's say that I created a snapshot of 1GB, and after some hours I delete the snapshot, the cost will be $0.05 or will have a lower cost since I not used a full month?

My idea is to automate the creation and deletion of snapshots per day/3-days (still thinking about it)
And I'm asking this question to have an idea about how it will cost to me, because in case of full charge of a month, everyday would be $0.05 per GB, ending in $1.5/GB per month.

Thanks