With all my talking about jewelry, vinyl, and other thrift-able knickknacks, I haven’t take the time to talk about another secondhand favorite of mine: first edition books. The first edition of a book is typically the first run of books produced. The most collectible and/or valuable of which is the true 1st/1st - which is a first edition first printing of a book, to be specific.
Publishing companies hedge their bets against a flop by doing a smaller print run of books, and then printing more once the first printing of an edition sells out. So you can have two books that are both first edition: one a 1st printing, the other a 6th printing, but the true 1st/1st is much more valuable (though virtually indistinguishable from the later printing). Often, the edition is either “stated” or identified by a series of numbers on the bibliographic info inside the front cover (this video pretty much says it all)
So, why do I buy? Book scanning software often cannot tell the edition or the printing, so most pro flippers at thrift stores often don’t spot them and collectors will pay top dollar for the right version in top condition. And with used books usually running pretty cheap, it’s worth the investment for an interesting-looking book or two - and you’ll have decent luck pick one up anywhere you can pick up a used book.