2011 Apple iMac 27" Intel i5 2.7GHz 8GB RAM 512GB SSD AMD Radeon HD 6770M | eBay
iMac 27" 2.7GHz (Mid 2011) | mac of all trades
Apple iMac 2.5Ghz i5-2400S (Mid-2011) *No HDD/RAM* – MSU Surplus Store
iMac Intel 21,5" Mid 2011 EMC 2428 - used original spareparts for Macs
NEMIX RAM 32GB (4x8GB 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
Third-Party RAM for 27-inch iMac Still Far More Affordable Than Apple's Checkout Upgrade Options - MacRumors