I was just wondering what enchanted books are used for?
I don't enchant many items, I usually just prefer to build stuff. But why would I want to enchant a book and then use that to enchant an item when I can just enchant an item using an enchanting table? Seems like a waste of time and resources to me.
You can store enchants on them. Say you have an excess levels available to you, you could go ahead and enchant some books, so that should you die and lose all your gear, you can return and enchant all your stuff!
On my server we (plan to) sell them in bundle packages for around £4.00. You get a totally random selection, or you can pay an extra fee and get a more class (we have Classes) specific set of enchants.