It would be edumacational to hear from somebody who really knows the details of the Bicycle Industry from that era (Citoyen? John Thompson?) cause he was there.
But perusing catalogs I've noticed that many Italian builders (and to a lesser degree, UK and France) really offered many pricepoints by varying the materials.
You could find (just an example) a Scapin with full SLX, or with full SL, or Tre-tubi, or Aelle or Zeta and these all still might have about the same level of pantographing, fancy cromovelato paint and chrome. You'd assume the build quality was similar, too, but who knows?
Clearly there was enough material cost involved in the tubing alone that price of the final bike was affected...(and component cost, too, of course).

Such a difference compared to so many manufactured products today where the cost of materials seems negligible to the cost of goods: it's all labor, transportation, and marketing. Especially marketing.

If we can believe the rumors, there were a LOT of "full Columbus" frames made that secretly substituted lower cost (usually Falck) stays and blades, but that cost-cutting was never mentioned and these got the Columbus decal...plenty of happy riders never knew (and still don't).