Scholastic Books sells childrens books through the elementary school classroom. (I'm sure they do a lot more.) The basic method is unchanged for at least 40 years: each month you get a color flyer listing books and prices. Most of the books are paperback, sometimes there are activity books; you can get a copy of the flyer from this page.
When I was a kid the price was 40 to 75 cents, I think. When I got back into it because of my kids, I saw that the prices are now 2.95, 4.95, and so on. It was a pain to fill out the order -- round up and subtract 'n' nickels at the end. Since a parent volunteer aggregates the orders and checks them, I can't imagine the work involved.
So I was pleasantly surprised to see that the latest flyer rounded everything up to whole dollar amounts. I'm not naive, I know the economic reason, but it's still way more convenient.