You should also give due consideration to the reputation of the manufacturer of the product. For example, if you want to buy silver bullion bars, you should opt for any of the big brands like Engelhard, Sterling Silver, Wall Street Mint Bars, and US Assay. The main reason for opting for big brands is that they make ingots of 99.99 percent pure silver and their name is enough to sell the ingot in the market. Most of them manufacture the 10-oz and 100- oz sizes ingots.