Do not forget about the 'latte effect'. You must include in the cost in books the opportunity cost of not investing that money instead. Assuming an average 12.

Do not forget about the 'latte effect'. You must include in the cost in books the opportunity cost of not investing that money instead. Assuming an average 12.5 euros (13.70 dollars) per book, one book read every 14 days, and 7% return on investment, you actually spend 4527.97 euros every 10 years on books. Over 30 years that number jumps to 31914.92 euros. Note: I used https://financialmentor.com/calculator/latte-factor-calculator https://financialmentor.com/calculator/latte-factor-calculat... to calculate.