eBay with Best Buy have the ZAGG Nomad Book Keyboard Folio Case for Most Tablets Up To 10.5″ (Black, 103201562) on sale for $25 with free shipping.
Compatible with 10.5″ iPad Pro, 9.7″ iPad Pro, 9.7″ iPad (2017-2018), iPad Air 2, iPad Air, Samsung Tab S3, and Samsung Tab S2 models.