Engineering textbooks (UNM ECE, ME, CE, BME, CHEM-E). The current-edition required textbooks for the core engineering sequence have meaningful used-market value: the mid-range collectible zone for current editions, the common reading copy to mid-range zone for recent prior editions. Older engineering textbooks (Stewart Calculus, classic Sedra-Smith, classic Oppenheim) sometimes have collector value too. The buyback rarely pays well for engineering texts because demand is harder to predict.
Premed and biology textbooks (UNM Health Sciences). Anatomy, physiology, pharmacology, microbiology textbooks all have strong used-market demand. Current-edition Netter, Moore Clinically Oriented Anatomy, Goodman & Gilman, Robbins Pathology — all the mid-range collectible zone used. Older editions still sell at common reading copy range. The buyback usually offers something competitive on these only if a UNM HSC course is reusing the exact same edition. See the medical and nursing textbook donations page for more on health-sciences titles.
Math textbooks. The Stewart calculus series, Hass-Weir-Thomas, Strang Linear Algebra, Lay Linear Algebra, Rudin Real Analysis (the famous "Baby Rudin"), Munkres Topology — these all have steady used demand and sell well year-round. International student editions priced lower than US editions are a complicated case; I evaluate them individually.
Computer science textbooks. CLRS Introduction to Algorithms, Sipser Theory of Computation, Tanenbaum Operating Systems, Dragon Book Compilers, Knuth The Art of Computer Programming — these are the ones I always pull aside in any UNM library because they hold value for a decade or longer. Current editions are solid mid-range collectible value older first editions are sometimes much higher.
Business and accounting textbooks. Lower demand than STEM. Most fall into the "buyback if they want it, otherwise Amazon trade-in if they accept it, otherwise text me" tier.
Humanities textbooks and readers. Anthologies, photocopied course packets, custom UNM editions are usually worth nothing on the open market. The exception is signed first editions of literary works — those are pillar territory; I have 59 author authentication pillars covering most of the canon. If you have a personal library that includes inscribed copies, those are worth flagging separately.
International / foreign-language textbooks. Spanish, French, German, Mandarin, Arabic, Portuguese textbooks at UNM cycle through international students and faculty. Some have significant used-market value (Hugo Carrillo readers, classic anthologies of regional literature) and some are worthless. I evaluate individually.
Required reading novels and plays from English / literature courses. If they're new copies in good condition, they sell for modest value each. If they're heavily marked up, they're recycle-only.
Older edition textbooks (2+ editions back). The buyback declines these. Amazon often declines these. But the open used market has steady demand for prior-edition copies at common reading copy range especially in subjects where the content barely changes (calculus, classical mechanics, organic chemistry). This is where I'm consistently the best outlet in the metro.
Course readers, photocopied packets, custom-bound UNM-specific editions. Generally worth nothing in resale. I take them as donations and they go to recycling. No need to feel bad about it.