I concur. Just think of the number of wasted trips dealers make to view that item in 'mint' condition that turns out to be a piece of cr*p. In effect, you're paying a 'finder's fee' at a fair from one of these dealers, which saves you time and effort in tracking old airguns down. Using Tim Dyson as an example, it is possible to attend a fair and come away with a near complete Webley collection or maybe with that one pistol you were previously missing. It may not be cheap or bargain basement but the opportunity is there and a prospective buyer can make their own mind up when viewing. Personally I think our hobby benefits from the presence of specialist dealers.
John