I'm trying to understand how the price estimation works for Azure Data Factory from the official guide, section "Estimating Price -

Meanwhile, I see, as they mention "In total, it takes 292 hours to complete the migration" it would include listing from source, reading from source, writing to sink, other activities, other than the data movement itself.

If we consider approximately, for data volume of 2 PB and aggregate throughput of 2 GBps would give

2PB = 2,097,152 GB BINARY and Aggregate throughput = 2BGps --> 2,097,152/2 = 1,048,576 secs --> 1,048,576 secs / 3600 = 291.271 hours

Again, these are hypothetical. Further you can refer Plan to manage costs for Azure Data Factory and Understanding Data Factory pricing through examples.