Billresh --No ,it is a totally different animal . The above original poster had high quality U.S. material with cert's . The only way your going to get his prices is if your doing the same as him with your purchases .
After having a few chats with some dealers, I've decided to go the auction route. Don't really have any hard data to impart; just have the distinct impression that the auction approach will likely yield better results even after commission, given the nature of the material that I have. Don't need the money right away, since I will just be giving it all to my son for his wedding and my grandson for his college fund, so I'll be patient and take my chances on the market. Thanks to everyone for your comments.
Oracle: good luck. Let us know, if you don't mind, how things turn out.
billresh: I agree with floortrader about world wide collections. You may want to have an offline exchange with him to get more feedback as floortrader seems to be among the most active buyers of worldwide collections at auction who post here. He knows the market well for those types of collections. Much will depend on what you have; how many higher priced items you have and in what condition; and the overall market.
I downsized a world wide collection during the past two years. Some higher priced items went to auction and sale still pending (I'm not in a big hurry). My France & colonies collection went for about 6% of catalog, after seller commission. But that particular market was and is weak, except for a few individual countries. The French/St. Pierre market is decent, but I kept that for my North America album.
The remainder was donated to the Rocky Mountain Philatelic Library. My Italian area catalogued around $3,000, but I included it in the donation as I wasn't expecting a good sale at auction due to not enough complete sets. And so on.......good luck.