Nice to see LDW going greedy like EA and selling extras like the game guide for another $10.. Just look at steam games. Updates with new content are released even years after release for free..
Actually, if you noticed under Developer's Edition features, it says that the game guide itself is included in the purchase of the game from the LDW website, along with the soundtrack and wallpapers. So the 19.95 nets not only the game but those three things as well.
The separate game guide is available for purchase for those in the future who would like to purchase it after getting the game from a different website.