Amazon.com: Dell Optiplex 390 Business High Performance SFF Desktop Computer PC (Intel Quad-Core i5-2400 up to 3.4GHz, 8GB DDR3, 1TB HDD, HDMI, DVD, Windows 10 Pro 64-bit) (Renewed) : Electronics
NeweggBusiness - 4GB Memory RAM for Dell OptiPlex 990 USFF, 390 Mini Tower, 390 Essential Desktop, 390 Small form Factor, 790 Essential Desktop 240pin PC3-10600 1333MHz DDR3 DIMM Black Diamond Memory Module Upgrade
Amazon.com: Dell Optiplex 390 Desktop Computer i3 3.2GHz 4GB RAM 500GB HD Windows 10 Professional w/19 LCD Bundle-WiFi Adapter, Keyboard and Mouse : Electronics
Restored Dell Optiplex 390 Desktop Tower Computer PC with a Intel Core i3 3.10GHz Processor 4GB RAM 250GB HD DVD-RW HDMI and Windows 10 Home Premium (Refurbished) - Walmart.com
Restored Dell Optiplex 390 Desktop PC Tower System Intel 3.1GHz Processor 4GB Ram 500GB Hard Drive DVDRW Windows 10 Home Premium with 22" Dual Screen Dell LCD's Computer (Refurbished) - Walmart.com
Restored Dell Optiplex 390 SFF Desktop Computer Intel i5 3.1Ghz 4GB RAM 250GB HD Windows 10 Pro PC - Walmart.com