It is rare of a different type. There were 250 stainless and 250 black with stainless cylinder. But they are just a modified version of a normal production gun of which 1000s were made. It is known that JR still was sitting on a bunch of them NIB. Word is that they were being purchased as a lot by an investor.
Real collector rarity would be an original Sharps rifle or a Maxim machine gun or silencer. Something that was made in low quantity and long ago brings a higher rarity factor to the gun. How many original 1873 rifles in 32-20 had a 30" octagon barrel, crescent butt plate, and full tube mag? And how many are left today?
Someone with enough money can have one of these JRC500s made pretty easily.
I bought my stainless JRC a few years ago for much less than someone here reported paying for a new one in the last 2 years ($1800-1900). And i got 200 rds of 5.56 in the deal too.
The JRC would most likely sell fastest on gunbroker. But you might be able to squeeze a few more pennies out of it at a LGS on consignment. In a year... It is a beast of a gun, and only speaks to a select few. And being a JRC wont mean much to most folks. I had no idea who or what a JRC was until after i bought it. I was buying a 500 SW and paid a fair price for one.
I do think the JRC500 is much better looking than the odd underlug versions. And in a place where one would carry a 500SW, the JRC would excel because of its quicker draw and general better handiness.