I am a silver/gold stacker. I have a local coin shop where I buy my 90% silver(half dollars, quarters and dimes). The rest I use two online bullion dealers, provident Metals, and JM Bullion. If you are looking to just add ounces, stick with generic bars and rounds. JM Bullion has weekly sales for rounds and bars, usually around $.69 to $.75 over spot. i don't like to pay more than $1.50 over spot for generic(private mint) silver, and no more than 3 dollars over spot for silver American eagles. Hope this helps.