Provident metal, Modern Coin mart, Silvertowne, Ampex to name and few and in no particular order. Some will charge shipping but the price over spot will be low, others are free shipping but the over spot price is higher. It's cheaper to pay by bank wire, check, money order etc... than using a credit card. Haven't bought bullion in a little while to tell you exactly who the cheaper one is but, just shop around on these sites a little.
I've been getting most of my silver from Modern Coin Mart. Quick shipping, great service, great price. I've bought from Scottsdale Silver and APMEX as well. MCM has the best prices on most stuff I've bought here recently.
I use www.comparegoldprices.com. I find it a quick way to compare the major companies premiums. Of course, always do your due diligence and pay attention to shipping charges.
I typically stick with Provident. I've tried others, and came back running. But like medoraman said, do your research before you make any decisions.
