<p>While I agree with everything that has been said above, I do want to say, for example a book I am collaboratively working with 20 other people in the Organization “Online Math Circle” creating free textbooks, as alternatives to the ridiculously priced AoPS Volume 1 and 2 Textbooks, 
and we plan on taking at most 6 months, but yeah 3 months is ridiculous. (PS writing in latex takes longer, since symbols are very meticulous and don’t just flow).</p>