His -11 is at least four turns away in a vacuum and while it doesn't end the game it still should be a huge momentum swing in your favor, though I am disappointed such an ultimate can't hit lands
Like most Magic: The Gathering cards, the value of Goldberry, River-Daughter depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Tales of Middle-earth Promos)
Remember that this deck is all about grinding out the win and slowing your opponent down with exerting, so cards like Double Trouble and The Carpenter can buy you enough time to set up your primary win conditions
Dig Through Time Often compared with Treasure Cruise, Dig Through Time offers good card draw and excellent card filtering
Buy Japanese if you want first access, original language, and Japanese print quality
These painted additions blend into the scene or background