How does state department of education buy books for schools?

I procured a textbook of Internal Medicine 1991 for 1300 local currency.
Take a look at this.
Harrison's Principles of Internal Medicine
Price: US$ 138.00 

than needs to be replaced by that.

are procured by a state, that means $100 per book multiplied by one million is equal to $100 million.

What do you think?