The Metroid Prime Trilogy which features all three of the acclaimed Prime game series is no longer being shipped according to Nintendo via Coffeewithgames
This comes after only four months of the game’s release and being the Gamecube games to get a new Wii control upgrades.
“Metroid Prime Trilogy…it is no longer being shipped. When first introduced, it was announced that there would be limited availability. However, a reason for this was not announced. That being said, you may still be able to locate a copy via stores that specialize in previously played or used games."
Good advice from Nintendo there, while you’ll not be able to find it new in many retail game stores you should be able to find it second-hand but the longer you wait the more collectable it’ll be and then the price will shoot up back up to full price as more fall into the hands of collectors.