Goldshark, www.goldshark.com, is a website that compares prices from various PM dealers. You pick the type of coin or bar you are interested in, and the site pulls up the latest pricing info from several dealers.
Many of the well-known dealers frequently come up: Apmex, Gainesville, NWTM, Provident, etc.
For example a recent search for $1000 face of 90% silver coins produced a list of vendors with prices from $22,500 (right about at spot price) to $23,200 (about $1 above spot) when the spot price was 31.60.
You still have to do your own diligence though, because at the time this search was done, Tulving was selling 90% dimes/quarters at 0.40 below spot and 90% half-dollars at 0.10 below spot, and Tulving did not come up on the Goldshark search.
Goldshark could be a good place to start your search to get a good idea of a sampling of the deals available.
[pmbug note: this post was merged with an earlier thread]