I think that any gun's value is likely to be based on how bad someone wants to buy that particular firearm....same for jewelry, real estate, etc. I bought a fine model 32 two(2) barrel set 7 or 8 years ago for $1595 with the Simmons ribs and the single trigger installed by Remington. Today that set with two barrel case would likely sell for $3K....if you could find one in that high condition.
Tom

Luck is the residue of good intention and hard work.