Nice deck, I think that with some addition it can be tested in a competitive field. First of all, I would consider adding the blue color to play cards like
thought scour, which seems to be pretty powerful in this deck. I would cut some expensive cards and keep the average converted mana cost below 3-4. I would add some disruption in form of some abrupt decays and a one of
maelstrom pulse. I really love the tree and the wurm as beaters, but I would also consider
grim flayer and
tarmogoyf if you have money to spend. As for the mana base, I would add the new BG fast lands. By the way, nice budget deck with nice interactions