Never thought about pawn shops. All the thrift stores by me have 98% before 1970, with the vast majority being Roger Miller, Andy Williams, Sing Along with Mitch, and Al Hirt. Most post 1970 releases consist of Barry Manilow and Barbra Streisand. Once in a while I’ll hit the jackpot, but those times are few and far between.
I signed up on Discogs and plan on doing more exploring once I get Christmas money.