Hi Juice,
In your mind, what makes a knife overpriced?
The knife is not properly priced for the makers position in the market. The knife is over priced for the materials used. The knife is over priced because it is a "trend" knife. Trend knives usually start right after a maker (particularly at a slow show) runs around telling anyone who will listen that they "Sold out". They are then more than happy to share with every maker how they made the knife, etc.
Those makers who like to "walk down the path after it has been created" will come in and charge close to what the trend setter is getting. Mindful not to be too close in price. They can then pick up some of the left overs. This is especially true of folders. As folder collectors seem to want to get "all of them"...more so than fixed blade collectors.
You bring up Scott Cook and Ernie Emerson and are discussing "High Demand After Market" prices. This is where collectors will sometimes pay grossly high prices for knives.
That market is a whole different conversation/thread. As the rules, cycles and pricing are more volatile than any other market out there. This is particularly true in the tactical folder market. As well we are now starting to see this in the Loveless (and his type) after market. Every one...except one person I know of..

thought the prices in this market would just keep escalating; and it will for some of the knives.
One of the smartest things Ernie did was not have his primary prices chase the after market prices. Ken Onion was very mind full of that as well.
I'm also wondering what the difference is between a top market position and being a "fan favorite" on the forum. I would have thought that they'd be related
Yes, they can intersect...but generally don't unless they remain a fan favorite for several years...most don't make it that long.
Here you see several of the more outspoken forum members keep posting pictures of their favorite makers work. Possibly giving the impression that they are a forum favorite...when in fact they are more of a particular collectors favorite. Even though when a picture is posted many forumites "Oh and Ah" over the photo. Often by members who don't own one of that makers knives...but still appreciate it.
Forum Favorites often times arise from the ranks on the forum. New maker keeps posting pics, contributing to the forum in other areas than just their own. Often times friendships form and the maker starts to sell on a forum. An influential forumite may buy a knife and tout it as one of the knives to own.
Ask any marketer and they will tell you the best marketing tool out there is "word of mouth". Especially if recommend by a well thought of member! Pure Gold!
This doesn't mean that a Forum Favorite can't become a market leader. It generally doesn't happen that way.