It's not a "premise". That's what the market value of anything is. I can have some view of what my guns are worth, but the real value is determined in a free and open market when others can accurately assess what is on offer and make their choice about what it is worth in competition with others of like mind.
Auctions are a relatively good way of determining value. See Rocketman's pricing charts.
Absolutely true. But auction results are often influenced by the quality of the presentation. I have little doubt that if I wrote the description and provided the photos, I could double the final selling price of this gun. The seller definitely hurt himself by not doing is homework and not presenting the gun in its best light.
That said, price discovery is a lot easier for common items. There are dozens of Sterlingworths on Gunbroker every day so it's a simple matter to look at completed auctions and get a good sense of value. When only one or two examples of a particular item come up every year, it's much harder to gleen much accuracy from auction results.
