Calculus books also fall in the same ball park: https://www.amazon.com/gp/bestsellers/books/491544/ref=pd_zg_hrsr_b_3_5_last https://www.amazon.com/gp/bestselle

Calculus books also fall in the same ball park: https://www.amazon.com/gp/bestsellers/books/491544/ref=pd_zg_hrsr_b_3_5_last https://www.amazon.com/gp/bestsellers/books/491544/ref=pd_zg... some of them are almost $300, OMG...