Blizzard is about the easiest gaming company to work with in terms of library services. All Blizzard asks is that one copy of their software be purchased for each computer used in the program. All of their relevant licensing information is available at the Blizzard LAN Events page. Essentially, as long as you don't make money off of your program, you only have to pay for the software and at least one subscription to download patches. Feel free to confirm any of this with the email address provided at the above link. In fact, if more libraries ask for help Blizzard may see the free advertising and subscription recruitment potential we can offer.
World of Warcraft (WoW)is currently made up of the original game and two expansions: The Burning Crusade (BC) and Wrath of the Lich King (WotLK). WoW can operate on its own, but there is no access to material, areas and certain races/classes available through the expansions. BC will not work without WoW, and WotLK will not work without BC; incidentally, patrons who own the game and all expansions will not be able to participate in a program if all three sets of software are not installed.
Current pricing will run about $79 for all three sets of software if purchased from a store. Amazon, for instance sells the World of Warcraft Battlechest (WoW and BC bundle with game guides) for $36.99, and similar deals can be found elsewhere. The WotLK expansion stil must be purchased separately. Subscription pricing choices are monthly at $14.99, every three months at $41.97, or every six months at $77.94.
Another purchase option would be to download the 10-day Free Trial of the original game and upgrade to the full-paid subscription. You would then need to purchase the online upgrades to BC and WotLK. A slightly more detailed explanation of this method can be found at the Blizzard Support Authentication Key FAQ.