The Tuxen is the most expensive at $50, and it's also the case that looks the nicest. It offers full protection with a vegan leather front cover that has a microsuede lining and a polycarbonate hard shell to protect the back of the iPad.
The Octane is designed to offer more protection, so it's thicker. It has the same vegan leather cover and polycarbonate back shell, but it also comes with a textured bumper for better protection against drops and its backing is clear so you can see the iPad. Like the Octane, the Clarion, the most inexpensive case we looked at, offers a clear back shell so you can see the rear of the iPad. It has a vegan leather front cover and its backing is actually flexible.
We liked all three folio cases, but there was a problem that afflicted all of them -- the stand feature built into the cover. All three have covers that fold back to be used as a stand, but the tab on the back that holds the cover in place means the iPad doesn't lie flat when it's placed on a surface like a desk. For the Clarion specifically, the latch was weak and wouldn't reliably keep the iPad in place.
All three cases come in a wide variety of colors and can be purchased from the Incipio website. The Tuxen is priced at $50, the Octane is priced at $40, and the Clarion is priced at $34.99.
On Amazon, the cases can be purchased at even lower prices, depending on color choice. $31 for the Tuxen, $27 for the Octane, and $22 for the Clarion.