Well please enlighten me on the importance of one adapter that cost $15 to make up vs. the Rejuvinator that cost over $1,000 new, and is no longer made. Is the BK 470 unit unusable without the CR23 adapter or is the CR23 adapter unusable without the 470 unit?
Did the BK 470 unit even include BR23 and BR31 adapters in the foam case kit, don't think so, these were extra about $7.00 from BK back in the 70's now add for inflation and we have a value for an NOS adapter of $45 which means the 470 rejuvenator should be worth at least close to what it sold for new.
Let's flip this scenario around so that you understand my logic behind buying this adapter, it's really not about price but about common sense, and keeping things original, for the most part, guess if we removed common sense from the equation then only price remains, now price becomes the comparative factor, actually I think the guys that make up the CR23 and CR31 should be selling them for twice as much, these are definitely an asset to the hobbyist.
I do not believe in perceived value, for me the value is in the condition of the original BK 470 Rejuvenator since the 470 cannot be reproduced...most members on here can make up a CR23 adapter but none can build an original 470 unit to look exactly like the factory original, although I do agree that the adapters are difficult to find (not impossible) the same argument can be made for finding a good clean working 470 Rejuvinator.
I honestly believe that $30 is very fair for the home made adapter, and $45 is very fair for a BK original adapter, now $60 for the 470, seems like I stole it, but heck that's what the seller had listed it for $60 obo with his phone number on CA CL and it was up for 3 weeks before I offered him his full asking price.
My budget for the 470 was $125 with the correct adapter so I'm still within my original price point, guess I should start looking for the $100 units and just the sell off all the adapters for $100 and get a spare rejuvenator for free...hmm...all points to ponder IMO.