Sorry to be so late. After taking a look at my a particular snapshot in my recent invoice, what I found was:

snapshot (nyc1) 1.25GB Droplet Snapshot 39 hours $0.01

So apparently DO doesn’t want to bother with how it doesn’t exceed 2GB but is 1.25. It just rounds up to the next biggest integer.

Or maybe it doesn’t want to bother with charges below 0.01. If that’s the case, I should be able to save this snapshot for 2 months before it gets more expensive.