It's the grade of aluminum that's used that makes the biggest price difference. The Weaver mount, being, that cheap may have sloppier tolerances but I'm not sure on that. The $29 EGW would be their standard model that is made from 6000 series (6061 I believe) aluminum. It's fine for most applications. The $49 model would be an HD and is likely made from 7000 series aluminum which is harder/stronger than the former.
Bookmarks