The rest of the budget is spent on starting to upgrade the lands, moving towards duals that enter untapped
...you are going to be zooming through your deck while keeping your opponent's forces at bay, while he or she is struggling to get any damage in at all
The biggest concern with playing monocolor decks around a niche mechanic like energy is the limited pool of cards available, but Nissa really patches any holes on both sides of your gameplan
To offset this downside, you can have a [c]Blood Artist[/c] in play, which make your opponents lose one life every time instead
The life loss is usually negligible in EDH, so this card tends to see a lot of play, especially in elf decks
You share life totals and are generally trying to win the game together