Three publishers will drop the agency model that kept eBook prices the same across all marketplaces, and the eBook price wars have already commenced. PaidContent confirmed yesterday that HarperCollins prices have already started to change.

Last week, a federal judge approved a settlement between between Hachette Book Group, Simon & Schuster and HarperCollins and the Department of Justice. Soon eBook marketplaces can sell some digital books at a discount, reigniting the eBook price wars.

Prices on Hachette and Simon & Schuster digital books still contain the “This price was set by the publisher” tag on Amazon, but their price restrictions will also be lifted as part of the agreement. In the meantime, we took a look at the most expensive books from these publishers–a way to track the changes in agency model books.

From Hachette, the most expensive book is The Twilight Saga Complete Collection by Stephenie Meyer, a $46.99 boxed set. The Casual Vacancy by J.K. Rowling is the publisher’s most expensive single eBook at $17.99.

From Simon & Schuster, David McCullough Library E-book Box Set by David McCullough is the most expensive, selling for $129.99. The most expensive single book was The Bass Handbook of Leadership by Bernard M. Bass and Ruth Bass, selling for $99.99.

At the same time, both publishers also have a number of free and 99-cent eBooks. Follow this link to see the lowest priced agency model books from Simon & Schuster. Click here to see the lowest priced books from Hachette Book Group.