Like most Magic: The Gathering cards, the value of Feed the Machine 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 (Archenemy Schemes)
The Prismatic Bridge has you reveal cards from the top of your deck until you find a creature or planeswalker, putting that card onto the battlefield under your control
The magical Christmas-land scenario where you get a turn 3 win(ota) looks like this: Turn 1: Play a land, cast Sol Ring, drop two cheap creatures like Rograkh, Son of Rohgahh, Ornithopter, or Ornithopter of Paradise
One of these is an amazing control-oriented stadium that can directly interfere with top strategies like Gardevoir ex and Raging Bolt ex
Even pulling them from packs in gem mint condition can prove very difficult