Amazon offers preorders of ZAGGkeys Folio Keyboard Case for iPad Air in Black, model no. ZKFHFBKLIT105, for $79.99 with free shipping. That's the lowest total price we could find by a buck. It features a Bluetooth keyboard which purportedly has 30% more typing space than similar cases, backlit keys, and three months of use on one charge.
For its Prime members, Amazon offers the Photive SlimPad Ultra Slim Smart Cover Case for iPad Mini in five colors (Purple pictured) for $9.95 with free shipping. (Non-Prime members can spend $35 for free shipping, otherwise it's $8.22.) That's $30 off list price and the lowest total price we could find. It is able to transform into a stand and has built-in magnets to support Apple's sleep and wake feature.