Several years ago, being somewhat of a newbie. We attended the Convention at the Orleans where going through a ( Well Respected )dealers book, found several chips that were not identified correctly, as to being current: and being such a nice guy (debateable)I proceeded to inform him and at which time he promptly marked up the prices : also informed him that some of his chips that were marked Obsolete were common and still in use. Needless to say he did NOT alter those prices.
After making the rounds I over heard him telling another collector that these same chips were Obsolete and very difficult, yes even used the " Rare ", and that he really didn't have the time to fool with Indian chips and he would sell the 5 that he had at a discount, that way the buyer would be getting a good deal and could also make some $$.

Mr Nice Guy ( me ) spoke up and Screwed the deal by loudly announcing aren't these the chips I told you earlier were NOT Rare !!

A lot of the times sellers of whatever, are directly mislead by individuals ( dealers / other collectors) who hope to capitalize on the everyday hope of individuals to find a bargin and make a few bucks.