2003 GDM expanded edition of Ennio Morricone's "Per qualche dollaro in più" could be one. Years ago I threw in the towel in regards to find this CD for a reasonable price...
"I guardiani del cielo", released in 1999 by BMG-RCA, is another Morricone CD reaching the highest prices in the market.
The 2001 Image Music release of "Nanà", also by Morricone, is lately a really elusive CD.
Another GDM release of two Morricone scores, "Una pistola per Ringo" and "Il ritorno di Ringo", from 2004, use to sell for more than $100...
Anyway, the prices of rare CDs can change from one season to the next, and the devaluation of the physical CDs nowadays is a fact.

angeldibujo, January 10, 2021; 2:21 PM

Serpent and the Rainbow is known to be one of the rarest soundtracks.

dstrohmeng, January 14, 2021; 1:10 AM

That's true, dstrohmeng, although its price dropped greatly when Varèse Sarabande re-released it in 2016 as part of their "Little Box of Horrors" 12 CD collection.

angeldibujo, January 14, 2021; 8:29 PM

Oh. I wasn't even aware of that. Thanks!

dstrohmeng, January 15, 2021; 12:17 AM