I think only one person has hit the point I consider one of the very most important: Weight, and its distribution and therefore balance -- MOI (moment of inertia) actually. That "weight between the hands" feel. A "lively" game gun -- and after all, most of today's shotgun game shooting simulates lively game shooting (except trap, and I don't see this as a product for the trap or pigeon shooting segment. Of course this requires the gauge-appropriate frames already stated several times.

Also of huge importance to real performance is proper fit to the individual's dimensions. Unfortunately many American shooters don't realize the importance of this but most of those who shoot really well -- particularly at game or similar targets, do. If you make stock dimensions to order, then the choice of grip style is open too. And of course, also the choice of wood grade.

About equal in importance is quality -- actual throughout, as well as initially-perceived. The latter certainly includes fit, finish and choice by the manufacturer of suitable materials and finishes.

I personally think a gun offering these features could compete in a crowded field at a relatively low price point -- perhaps not exactly the price cited, but close enough. (And hugely important competitors in that crowded field are a myriad of used, good guns.)

Fred