YOu can buy it from entertainment.com. Right now they are 35% normal price, plus shipping. Normal price varies for the area. The Orange County book is much more expensive than, say, my area's book, or Arkansas's book, and so on.
So if there's nothing for Utah in a book, or nothing you would use, then just buy the least expensive book there is.
If you belong to "rewards" sites like my points or sunshine rewards, buy through them for the chance to get credit for the purchase.
There are others who buy just the card (which is all you need for HoJo at check-in) from ebay.
No matter what, be sure to get one that is good for your stay...they generally expire Nov 1.