My 12 y/o son is so excited. Found him a pristine Mid-2010 27" iMac for $100. Going to give it the SSD upgrade but he's stoked to start recording music with it :
maxupgrades.com: Dual SSD Drives kit for iMac 27 inch 2012 Models with Blade SSD Module with Heatsink and Power and DATA Cables
iMac Mid-2010 27 inch (A1312) SSD and RAM disassembly and upgrade - Much FASTER! - YouTube
HD Upgrade Kit for all iMac 2011 Models + Tools - 44.75EUR - OWCshop
Internal SSD DIY KIT for All Apple 27" iMac 2010 Models
How to Upgrade iMac Hard Drive (2009, 2010, 2011): EveryMac.com