This is so far beyond pointless that I am tempted to just ignore it but why not take a swing... It's friday after all.
The average user spent "3,600 worth of time" creating all those emails. That is not to say that recreating them would cost exactly $3,600 because, as you can imagine, the email contents are NOT stored in the users' head. Recreating them all would be extremely difficult (and therefore come at a much higher price). Backupify has an interesting thesis (and certainly backups are valuable) but not assessing the *forward value* of those emails means that you pretty much cannot act on that figure.