Apple iMac 27" Late 2013 i7-3.5GHz/16GB RAM/256 GB SSD/ GPU GTX 775M 2GB A1419 | eBay
Configure your own 21.5-inch Apple iMac (2013) at OWC
Apple iMac 4K Retina 21.5" Desktop - 3.3GHz Quad-Core i7 - 16GB RAM - 256GB SSD - (2015) - Silver - Best Deal in Town
Mac Pro 2013 Memory Upgrade Sale
Amazon.com: Timetec 16GB KIT(2x8GB) Compatible for Apple DDR3L 1600MHz for Mac Book Pro(Early/Late 2011,Mid 2012), iMac(Mid 2011,Late 2012,Early/Late 2013,Late 2014,Mid 2015), Mac Mini(Mid 2011,Late 2012) MAC RAM : Electronics
Late 2013 iMac review: Faster than before, but the gains over previous models are modest | Macworld
Memory upgrade: Apple iMac 2012/2013/2014 (Howto)
16GB KIT 2X 8GB for Apple iMac 2.7GHz 21.5" Late 2013 2.93GHz 27" Late
iMac (27-inch, Late 2013) - Technical Specifications
16GB Memory Upgrade Kit for 2012-2013 iMac 21.5-Inch