True, John, but I'd say this is not so much a valuation as a rough prediction of what someone out there might pay in an auction situation. I know the difference is quite subtle, but when I do (admittedly subjective) valuations, I'm balancing what someone out there might pay with a notional 'true value' ie. of one gun versus another, rather than a pure market prediction.
So, for example, I would put a cap on the value of a Junior because if it went too high, you might as well have a Senior or a Premier for only a little bit more.
But how much someone (albeit pretty desperate) might pay for eg. a Webley oil can or bottle in competition with another desperate soul on the auction site, seems largely unconstrained by relative values. Surely that is why they can spend as much on an empty tin can as on a lovely condition Webley Senior!
I've lost my train of thought now and even I don't understand what I'm saying, but I think I did when I started... Doh!