The mints are working at whatever capacity they have.
It is not expensive to get rounds minted. The old man Pawn Guy did it... last time I checked it was .59 per round but that depends on purity of the bars you give them.
The us mint is different, they do not make blanks, that is contracted out based on demand estimates and have a long lead time to get extra ones.
Junk silver is not .999 and while there is some above spot it is not melted down anymore
Dealers near me have always paid over spot for eagles
By junk I meant 0.9 https://www.coinflation.com/coins/1946-1964-Silver-Roosevelt-Dime-Value.html