How to upgrade RAM in the (Mid 2017) 5K iMac and save up to ~$900 [Video] - 9to5Mac
Apple iMac (27-inch, 2017) review: Apple doesn't mess with success - CNET
A-Tech 64GB (4x16GB) RAM for Apple iMac 2017 27 inch Retina 5K | DDR4 2400MHz SODIMM PC4-19200 2Rx8 1.2V 260-Pin SO-DIMM Memory Upgrade Kit at Amazon.com
Amazon.com: OWC 32GB (2 x 16GB) PC19200 DDR4 2400MHz SO-DIMMs Memory Compatible with Mac Mini (Late 2018), 27" and 21.5" iMac (Mid 2017), and Compatible PCs (OWC2400DDR4S32P) : Everything Else
Apple iMac 27-Inch With 5K Retina Display (2017) Review | PCMag
Apple iMac 27 Inch 5K 3.5 GHz Core i5 1TB Fusion 64GB RAM 4GB GFX 2017 – Quality Macs
Apple iMac Retina 5K 27 Inch 2017 Intel i5 16GB Ram 1TB NVME SSD Radeon Pro 575 GPU for Sale in Falls Church, VA - OfferUp
Apple A Grade Desktop Computer iMac 27-inch (Retina 5K) 4.2GHZ Quad Core i7 (Mid 2017) MNED2LL/B 16 GB 2 TB HDD & 256SSD 5120 x 2880 Display Dual Boot Hi Sierra/Windows 10
Refurbished 27-inch iMac 3.8GHz 8-core Intel Core i7 with Retina 5K display - Apple