It depends:
(1) How much do you wish to liquidate?
If you are liquidating $1000 bags of 90%, Monster Boxes of ASEs, or tubes of AGEs, you should gravitate to the biggies: Tulving, Bullion Direct, and Apmex, and others. If you've only got a 100 TOZ or less to sell, you can look to sell here on RealCent. Selling EBAY will cost you fees, but it could be the best option for you depending on what you have for sale.
(2) What will you liquidate?
If you've got AGEs, ASEs, tubes of maples, in quantity, you can sell them anywhere. It's very liquid stuff. As you get further away from these, you have do your research to find the best market.
(3) Who did you buy it from?
If you bought your PMs from one of biggies, you can easily sell it back to them. If you bought from your local coin dealer, maybe you might not want to sell it back to them as their margins can be high. If you picked it up in coin shows, you're sort of on your own to find a buyer.
(4) When do you need the CASH?
If you gotta have the CASH right away, you need to sell it a discount to move it quickly. The bigger the discount, the more the buyers will show up. However, if you can wait a bit, then sell it for a reasonable price, but at a price that buyers usually pay. I would suggest selling your PMs somewhere between an APMEX BUY price and an APMEX SELL price. If I were selling, I would not expect to get the APMEX SELL price for my PMs. Do some research and see at what price you need to place on your PMs.
Hope that helps a little.
