Perimeter fencing has been mentioned but cross fencing has not. That can easily be multiples of your perimeter number, particularly if you’re talking about horse fencing.
Is there running water on the property? Is it usable? Having a good stream, or pond, can save a very large amount of money per year in water costs (either a public system or a private well system).
To enable you play “what if?” a little more easily use Google Maps or Earth and print out an aerial photo of the land. With that in hand you can look at multiple possibilities for division.
G.