Can you buy published books?

I have figured out a way to keep books without a mod. Take the book from your sim's inventory and put it on a table. When you click on the book, you will have the option to "make a copy". Do that and another copy of the book shows up in your sim's inventory. Then put the original book back in your inventory and publish it as usual. The copy will stay in your inventory or you can put it on your bookshelf.