"What ho! this fellow is dancing mad; He has been bitten by the tarantula"--EA Poe

My advice to a fellow sufferer: stick to thrift stores and junky antique malls--but not primarily the major national chains like Goodwill or Salvation Army (or Oxfam overseas), which tend to cherry pick vintage rock and jazz and resell them online. For $10, you can buy 5-20 records that you've never heard of, including rare genres and international music--some of which will probably be as good as what you do know, and you'll learn something about the history of music in the process.

The most valuable record I own: https://www.discogs.com/sell/list?master_id=336192&ev=mb

$1 for an original pressing, from a Habitat for Humanity thrift store; currently selling for $300 on discogs for $300 in VG / G; my copy is probably VG+ for both media and sleeve condition.

My local record store's selling Wish You Were Here with a really crappy sleeve (didn't even bother to look at the disc inside); mine is VG+ and cost $1 from Goodwill.