LG Electronics has 48″ LG Ultragear 48GQ900-B 3840×2160 4K UHD 120Hz OLED Gaming Monitor on sale for $699.99. Shipping is free.

Specs:

• Screen Size: 47.5″
• Resolution: 3840×2160
• Refresh Rate: 120Hz (138Hz O/C)
• Response Time: 0.1ms GtG R/T
• Panel Type: OLED
• G-SYNC Compatible, AMD FreeSync Premium
• Ports:
  • 3x HDMI 2.1 Input
  • 1x DisplayPort Input
  • 1x USB Type-B (USB 3.1 / USB 3.2 Gen 1) Input
  • 2x USB Type-A (USB 3.1 / USB 3.2 Gen 1) Output
  • 1x TOSLINK (S/PDIF) Output
  • 1x 1/8″ / 3.5 mm Output