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What’s the most you’ve ever spent on a book?
(thelemmy.club)
Excluding textbooks for classes, I bought this for ~$300 (several several years ago as a special treat)
Most of my collection is thrifted/bought from garage sales (for a quarter to a dollar usually) but I do have a handful of nicer ones.
£120 on a pristine copy of The Biographical History of Electricity and Magnetism.