For the OP.
It's an easy answer. The seller is looking for the person PT Barnum described.
Real world gun values are hard to keep abreast of. The Blue Book does as good as it can from the info provided to them. In fact, the RENE price guide is the same way. We rely upon information of what a gun will SELL for in CURRENT real world values. And if I'm not mistaken, the info for a lot of the Rugers in the Blue Book comes directly from our RENE Price Guide. I have filled out chet15's pricing request several times, but I will admit that I haven't for a few years as it's time consuming at a time I am usually busy. (I apologize Chad!) When Chad asks for help from us, we should give it to him, and then, he can use our info to build the price guide & pass it along to Blue Book. Then they get real world values as best as they can. But remember, by the time we get the info done, compiled, submitted, and sent to the publishers, it can be several months. Occasionally, things change.
Another way to gleen good real world values is to scan the completed gun auctions prices. The guns that actually sell. The biggest problem I see with that info, is we do not see the ones where the gun was described as "excellent, or ANIB" and the buyer pays a premium, only to return the gun because it's not as described.
Many sellers hope for a big return on something because they find out they have a gun that IS rare, or they THINK the gun they have is rare. If it is rare, then they post high asking prices, but fail to do an honest appraisal of the condition. They also hide the flaws by not providing good detailed pics. Or, the ones I love are the ones who THINK the gun is rare, because they see a SIMILAR one for sale that is rare & declare their gun is that one, or price it THINKING it's one of the rare ones.
All of the higher than normal prices are easily ignored by the informed. But we get surprised when one of them sells to the type of person PT Barnum described!
Lastly, there is a whole 'nother angle. A seller keeps a gun at the same sale price for years, until the collector market catches up with what he has to sell. I recall a NIB Hawkeye, 2 digit, (#84) that a gun show dealer kept for almost 3 years. I never had the $$$, & it finally sold. He had it priced at $1000 the whole time. Now,,, a 2 digit, NIB, goes for a lot more,,,,,,,,,,,,!