As I write this, silver is $14.50, ASE's are selling for $18 each on ebay (roll of 20, shipping included). That's a 25% premium, 21% if you figure shipping is $10. Even if you drive to the coin shop, you'll pay for gas, but don't pay sales tax! If someone is selling for $18, that means you can sell for $18. The only difference is the shipping, which is about .50/coin, or 3%. On the other hand, silver bars are selling at about $16 / ounce, which is 10% over spot.
But the point is not to buy silver at a low point, then turn around and sell it back at the low point..If you are going to sell at all, wait until it spikes back up... Me personally, I'm just a collector, don't do anything for profits, unless it is to save up for a coin I want
If there is a coin dealer in your area, then I would check it out and see what they that dealer has in terms of silver. Based in my experience of buying silver, I can get silver at a lower premium over spot if I buy at a local dealer and once you become a regular customer at that local dealer, then you might get an even better price on silver. It just depends on the local coin dealer. I prefer to buy locally but I also buy on line too. DYODD