If you’re just looking to stock up on silver, I’d recommend staying away from Silver Eagles. The premium on those hover around $15-19 over the spot price of silver.
If you’re looking to buy a lot of silver, the larger bars are the best bang for your buck. Lower premiums the more troy ounces in the bar.
It isn't just about the original purchase price. Practicality comes into play.
A SHTF aspect for 1 oz bars over larger bars is their easy passing.
A small silver coin/bar/round will have far more bartering power for the usual, small items most prominent in our daily lives.
One chicken? One ounce of silver, please.
(if it's one ounce of gold for the chicken...I'm going fishing!)
JMO, YMMV