Modern Commem Silver Dollars a bargain vs USA Classic Dollars as investors flocking to these during these times. A coin club presentation by a rare coin investment consultant illustrated this concept.
This has been my recent (the last ~2 years) method for silver stacking. I consistently get these from a local dealer at $21-22 each right now. Much better than the typical $30-35 for vintage Peace and Morgan dollars. From a silver content perspective...no difference.
And if you pick up the Uncs and not the proofs you can get some pretty low mintage issues as well. I picked up a fair number of pieces with mintages in the 20K to 30K range for melt value.