I noticed this add on Ebay and at first it seems like a great way to acquire silver coins. That is until you do the math. http://cgi.ebay.com/SILVER-COIN-LOT...56?pt=Coins_US_Individual&hash=item19baa91708 First, he's selling 8 ounces of silver coins, not 8 ounces of silver. The 8 ounces of silver coins nets about 6.56 ounces of silver. So at $27 per ounce, that's $177.18 in Silver, not the $216 you might thing if you forget the wieght of the other material in the coins you are paying for in that 8 ounces. That makes the sale at about 20-25% over spot. Not terrible, but not the bargain initially suggested.
You can get many lots at right around silver spot on ebay. The auction you posted is a pretty common 'tactic' to get those large profits.
20% over spot before you pay shipping... not such a hot deal in my opinion. Your local coin (or pawn) shop will probably do 10% or less for 90% silver with no shipping.
Not a good deal at all. I recently bought circulated silver coins (Canadian) for about 15% under spot! There are deals out there, you just have to be patient and look for them.