This article never gets specific, but I get the impression the author doesn't really know what "prime" means: how well marbled the cut is with fat. Salt isn't going to change that (although, again, it will improve your steak).
If tenderness is all you're after, you can use a jaccard on the meat; Google it, they're cheap. They put tiny little cuts in the meat to break up the fibers.
When people say "cheap steak" they usually mean skirt or flank. Can you even get prime skirt steak?