Managed to pick this 2007 iMac for $20 on OfferUp today that was stuck in recovery mode... several hours later it's back up and running again :) : r/mac
CMS 6GB (1X4GB) & (1X2GB) DDR2 6400 800MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Apple® iMac Core 2 Duo 2.4 20-Inch Early 2008 - B117 at Amazon.com
A-Tech for Apple 6GB Kit (1x2GB + 1x4GB) DDR2 667MHz PC2-5300 200-pin SODIMM for MacBook (Late 2007, Early 2008, Early 2009), MacBook Pro (Mid 2007, Early 2008), iMac (Mid 2007) - Memory RAM Upgrade at Amazon.com