Google said this method of moving large amounts of data between virtual machines runs at up to 8x the speed of scp.
It costs 2.6 cents/GB/month for taking a Persistent Disk snapshot. However, Google notes that the actual average cost comes out to about $0.003 per 500GB of data transferred because the snapshot used for transfer purpose is short lived (under 10min) and its pricing is prorated based on a granularity of seconds. “That means for less than a penny you can move a terabyte of data at 8x the speed of traditional tools.”