Sprint will be selling the HTC 8XT for $99.99 after a $50 mail-in rebate starting on Friday, July 19th. The HTC 8XT was originally announced in late June with a “summer” launch date. The HTC 8XT comes equipped with a 4.3-inch WVGA display, 1.4GHz dual-core Qualcomm Snapdragon 400 processor with 1GB of RAM, 8GB of internal…