If you have to ask, you likely don't care about the answer. The truly expensive bottom metal is not just the floorplate, but also a properly proportioned and finished magazine box that, for rifles that must feed each round, each time, are essential. Also, the quality of the metal to metal fit, floorplate release system and overall fit on a Sunny Hill, Blackburn, or Sound Metal Products unit will be far and away better than anything put out by the factory, especially after they're properly finished. You're not paying $300 for a warmed over Remington floorplate. Unless you're buying a Badger unit
