Super Six Pricing?

Seems like you never see a complete Super Six set-up (intake, barb and kick down linkage) sold as 1 unit. Looks like people are selling the intake and maybe the carb as a unit and the kick down linkage separately or maybe they don't have the kick down linkage. Here's 2 personal examples:

I've got a sweet running Super Six-equipped motor I pulled from a 65 Dart I bought - that had no kick down linkage on it. So if I sell the SS intake and carb to someone who has an automatic, now they gotta shell out more money for the kick down linkage or buy a Lokar or similar (and spend more money)

I have an 87 D100 I bought from my grandson. Him and his Dad installed a 72 slant motor/904 from a Valiant I gave him. Yes, you guessed it - it has a Super Six on it. They tried to fabricate a kick down based on pictures but its not right and doesn't work too well. So I'm in the same boat as the person who buys a Super Six without the linkage.

Edit: I did obtain the kick down linkage for the truck from over at .org.