Don't know, but would love to see a shoot off! A sercy, starts about $10,000. Merkel and krighoff a bit less. H&H and Purdy about $100,000+ (I shit you not, I stopped by both show rooms when I lived in London and got a price brochure) However, you asked about demonstrable difference. That probably is manifested in feel and balance. I'll admit that my Merkel is clubby, an H&H or Purdy will fit you like a glove and swing like a fine shotgun. They will also last 200 years. I've handled and shot a new ($90,000) Purdy O/U shotgun, they are quite remarkable.