For example, if you have Office365 E1, and you want to add the features of Enterprise Mobility + Security E3 for $8.80, why would you do so when Microsoft allows you to add F1 for $2.25, when F1 has all the same exact features?
Yes, Microsoft allows you to add E1 & F1 to the same user and combine the features.
Am I missing something? Why would someone add Enterprise Mobility/Security E3 to their E1 package, when they can get the exact same feature set in F1 for much less the price?
E1 gives you your mailbox and basic functionality, F1 gives you Intune, Autopilot, Security Features.