Apple iMac 27" 5K All-In-One Computer, Intel Core i5, 8GB RAM, 1TB HD & 128GB SSD, Mac OS, Silver, MF886LL/A (Certified Used) - Walmart.com
Today picked up a $20 2011 iMac 27” with working gpu too! : r/mac
Install memory in an iMac - Apple Support
Install memory in an iMac - Apple Support
NEMIX RAM 16GB (2x8GB Upgrade) DDR3-1333 PC3-10600 204-Pin SODIMM Memory for Apple MacBook Pro Early/Late 2011, iMac Mid 2010 27 inch 4-Core, iMac Mid 2011 21.5/27” , Mac Mini Mid 2011 at Amazon.com