... especially if they are pop/rock titles and were pressed in the 1980s.
If you Google "Loudness War", you'll come up some very good/important YouTube vidoes and Wiki articles on how absurd the loudness situation has gotten. Often newer CDs are re-marketed with "remastered" or "from original master tapes" ... and even if they were, the re-mastering is undone with the cranked loudness.
If you go to eBay, you'll often see Target or "West German" CDs fetching MANY times their orig. price. Not being "loudnessed" is the primary driver of renewed high demand and inflated auction prices.