Valuing Precious Metals

I have a question about valuing precious metals. I have tried several online gold value calculators and they all seem to work fairly well; however, after they give you the current market value, some say that you shouldn't expect to get that amount when selling. What percentage of current market value should you expect when selling your precious metals?

Also, I have a Platinum men's ring from Zales that I'm trying to value. Does anyone know how to tell the purity of the platinum? Is there a standard purity that Zales uses or a minimum purity that can be marketed as platinum?

"My place" buys silver bars/coins for $1 an ounce under market

Scrap gold and silver for 80%-90% of market depending on is much you have, purity.....

Don't know much on platnium and believe the rate was 80% of market.  I would think, but don't know, that a place like Zales probably uses pure.....maybe 950.

As far a I know there is no standard.  As long as its over 50-some percent they can stamp it "plat"

ive been getting 75-80 % on silver and 80-90%
 on gold depending on quantities

This article may be out of date, from 2006, and kind of a fluff piece but offers a little thought on the subject of platinum purity.......

http://online.wsj.com/article/SB114973105810474493.html

the key is to sell to the end user ie someone buying silver/gold, etc on craigslist. normallywhen someone buys gold or silver they pay a % over spot price when someone sells they get paid a % below spot. if you sell to the end user y ou can sell at spot rate and they save money and you sve money cutting out the coin shop, jewelry store or we buy gold store or whoever else would be the middleman.

you probably dont even need to go to craigslist. i have several buddies who buy silver with every spare dollar they have so anytime i come across silver i call them and we do a sale at spot price sometimes ill even get a bit more than its worth

That's a good idea...I'll remember that the next time I come across gold/silver in a storage unit.