Junk Silver US coins look to me to be about the worst possible way to buy silver. Almost very place I look that is a “reputable” broker Junk Silver carries a 30% mark-up to spot where 1 oz bars are 4% and Maple Leaves are about 15% or so.
I haven't seen this mentioned, but when junk silver is touted, it is always via face value as compared to actual weight in 90% silver. I have run across dimes and quarters that were worn so thin that they were worth much less in value.
Mebbe there aren't as many of them, but I'd hate to buy a sealed $100 bag for $1,500 and risk finding that many of 'em were so worn down that they were worth a couple of hundred bucks less.