“The Official Preppy Handbook,” by Lisa Birnbach, was published in 1980, retailed for $3.95 and now people are paying hundreds of dollars on Facebook Marketplace, Ebay, and other sites just to get a copy of it.
Got my copy in 2019 and sold it for 300% profit, it was good but a bit stuck in the 1980s. Much prefer true prep as it discusses more relevant brands like vineyard vines, etc.