27-inch iMac with Retina 5K display - $1600

Specs:
• 4.0GHz quad-core Intel Core i7, Turbo Boost up to 4.2GHz
• 16GB 1867MHz DDR3 SDRAM - two 8GB
• 1TB Fusion Drive
• AMD Radeon R9 M390 with 2GB video memory
• Magic Mouse 2
• Magic Keyboard (English) & User's Guide
• Accessory Kit

I've had this computer for 2 years and it is still fast and works great! Comes in original box. Price is negotiable.