I echo the thoughts of others - check a coin magazine. While many silver coins have numismatic value above the silver content, unfortunately some dealers only offer the bullion price during this "sell your broken gold and silver" craze. You are right to suspect that a dealer's quote might not be reliable. Besides, a dealer will generally tell you what he would pay, not what he would sell it for.
Also keep in mind that when silver slides in value, this week's estimates will have to adjust, too. Good silver dollars might end up back at $9 or $10 each.