The other thing to keep in mind is that you cannot just own and carry an electric outboard.
The big PITA factor in electric outboards is that you also need to own the battery. And batteries are big and heavy as hell and just a general PITA because they need to be carted around and kept charged and they have a finite lifespan even if seldom used.
This is one of those things where you really want to ask yourself does the PITA aspect of ownership overcome the cost of renting it when needed?
The old saying about the 3 F's comes to mind. If it flies, floats, or fornicates, it'll always be cheaper to rent it. It just might not be as much fun.
Grouse