The value is two Husseys equal one Purdey/H&H/Boss/Woodward. The difference is that if we are speaking of a best work gun, the chances of any given gun having originally been a best work gun are a good deal higher with the Purdey/H&H/boss/Woodward than with the Hussey. The market does not like uncertainty, as you can see from the advice on the barrel pits.

A best work Purdey, BV1-OQ1-CC3(significant use) = $21,000. A gun in this condition can have significant wear to blue/black, case color, and wood finish; it might even have a quality reblack and/or wood refurbishment. However, it will not have any barrel, frame, or lock issues; absolutely no burred screw slots!! A $16,000 Purdey, BV1-OQ1-CC4 = $16,000 should fit to a current condition description of, " heavy use, but no abuse." Occasionally, you will find a Purdey in CC3, or a bit better, but with barrel pits due to a short lapse in cleaning after shooting corrosive priming. Uncertainty about the barrels must be a big value hit.