Tony at Tradex showed me his custom built 9.3/.338 Lapua and told me the dies were over $700. I asked him why not a .375 RUM, same bullet weights and same powder capacity with factory ammo availability, cheap dies and reamers. He simply said he likes the Lapua case and 9.3 was his favorite caliber.
The important thing is that he is happy with rifle.
I once designed a .338 on a full length blown out .404 case to improve on my .340 WBY. Before I could realize this project Imperial came out with the .338 Imperial (same as the .338 Edge) and later Dakota came out with their .330 which fits a standard 98 and Remington introduced their .338RUM. The Lapua, though based on the Rigby case would also have provided the ballistic advantage I was seeking.
All of these offered factory ammo and reasonable production and reloading costs.
I still think a .505cal 525gr Woodleigh at 2400fps in a 2.65" .460 Weatherby case with a .5" neck would be the perfect DG cartridge in a standard 98 Mauser with a drop box mag with 4+1 capacity.
Now if only one of the major players would offer it.