On topic for the thread title, but off topic for the various comments, all of the aluminum frame vintage bikes I have sold have brought MORE than their same era equivalent from the same manufacturers (or in the case of Cannondale, their competition).

I have sold aluminum frame Treks from the late 1980s, Cannondales from the mid 1980s or newer, Miyata, and a few others. And in every case, they brought more.

While many on this forum (including me), much prefer steel frame bikes, the average buyers out there like aluminum frame bikes just fine.

I used to avoid vintage aluminum, no more, I learned a lesson there.