I think that if you do 25 of silver you will find it will have to be priced stupidly high to cover the cost of the stamping process, stamps, and I would say the cost of design but that isn't a real cost per say because you do all the artwork yourself? If you don't have the design say .999 silver or .999 gold you could save the cost of the stamps by using the same ones for the gold and silver
Problem with using the same stamps is that gold and silver dont weight the same so a 1 oz silver coin is different in size than a 1 oz gold coin
This is why my gold designs are double the weight of my silver designs for my Minted Seats line. With my binary rounds, I wanted them the same diameter as their silver counterparts, so the gold ones are thinner. I've actually reused one side of my 5oz silver dies to make 10oz gold rounds.
