Vintage groupset pricing
So I've lately been trying to find the answer somewhere on the internet but can't seem to find anything. How much did groupsets back in the 70s-90s cost before/after inflation? Was a groupset such as Dura Ace 7400 comparable in price to Dura Ace 9000? My assumption is that the older groupsets were relatively cheaper due to differences in materials and less complexity but I really have no idea.