I got a FREE 2013 iMac 21.5 with internal upgrades including Samsung evo ssd and 16gigs of ram. Then used open legacy patcher to install Mac OS Venture 13.5 beta. : r/osx
Installare la memoria in un iMac - Supporto Apple (IT)
iMac RAM-Upgrade für 21,5" Late 2012 bis Late 2013 | Apple RAM-Upgrade | Service | Level 16 Online-Shop
Upgrade SSD 512GB + 8GB RAM IMAC 21″/27″ MODEL 2012 2013 – Cd Care
Apple iMac 21.5-inch 2012 - 2013 RAM Memory - Macfixit Australia
Upgrade RAM Apple iMac 21.5 slim A1418
8GB Memory (PC3L-12800, DDR3L 1600MHz) for Apple MacBook Pro 15 inch A1286 Mid 2012. Apple MacBook Pro 13 inch A1278 - Mid 2012. iMac 21.5 inch A1418 Late 2012, A1418 Early 2013,
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET