In your other thread about the Pope stamps I mentioned
ebay and delcampe. Same idea here, but the souvenir program / envelope whole thing makes this a special Olympics collector item if sold like this. You pretty well have to search out the stamps separately I would think and see what they are worth and then list it ona site (if you want to sell it that way) and see what happens. Sometimes on the
ebay and other sites it takes a while to sell a special item. It might be worth while to list it as a buy it now item for a month (if you know the price you want to get). Otherwise start at a reasonable price and see if anyone is interested.
Just because the catalog says it is valued at xxx $ does not mean anyone wants it right now. It's nice stuff you have but you still have to find a buyer. Hope you do. I wish you good luck with everything.