Best Buy: Apple 21.5" Certified Refurbished iMac Desktop Core i5 1.6GHz 8GB Memory 1TB HDD (2015) Silver MK142LL/A
Apple iMac review (21.5-inch, 2015): 4K is optional, faster hard drives shouldn't be | Engadget
Apple iMac with 5K Retina Display (2015) Review | Tom's Guide
Used Apple A Grade Desktop Computer iMac 27-inch (Retina 5K) 3.2GHZ Quad Core i5 (Late 2015) MK462LL/A 8 GB 1 TB HDD 5120 x 2880 Display Sierra 10.12 Includes Keyboard and Mouse - Walmart.com
Amazon.com: Late-2015 Apple iMac with 2.8GHz Intel Core i5 Quad-core (21.5-Inch, 8GB RAM, 1TB) (Renewed) : Electronics
Apple Unveils New iMac 4K & 5K, Magic Trackpad 2, Magic Mouse 2, New Keyboard
Apple iMac 27" 2015 - i5 3.3GHz - 16GB RAM - 2TB HDD - Model Number MK782LL/A - Grade B Used - Walmart.com
Amazon.com: Late-2015 Apple iMac 21.5 with 4K Retina Display/3.1GHz Intel Core i5-5675R Quad-Core (21.5-inch, 8GB RAM, 1TB) (Renewed) : Electronics
Apple iMac 21.5" (Model 2015)- Core i5 1.6GHz Processor 8GB RAM 1TB HDD Wi-Fi Webcam OS Mojave USED - Walmart.com
2015 27-inch iMac with Retina 5K display review | Should I buy an iMac? | Macworld
Apple iMac with Retina 5K 27in (2015) review | Stuff