My first PC: Dell Optiplex 7010 Mini Tower with 1tb HDD , 16gb DDR3 RAM, i5- 3470 CPU, and AMD Radeon HD 7000 series GPU. Got it for only $150 : r/pcmasterrace
Refurbished: Dell Optiplex 7010 Business Desktop Computer Tower PC (Intel Core i5-3470, 8GB RAM, 120GB SSD, WIFI, DVD-RW, USB 3.0) Windows 7 Pro - 32 Bit - Newegg.com
Restored Dell Optiplex 7010 Desktop PC with Intel Core i5-3470 Processor, 16GB Memory, 2TB Hard Drive and Windows 10 Pro (Monitor Not Included) (Refurbished) - Walmart.com
Dell Optiplex 7010 Business Desktop(i5-3470 Processor up to 3.6GHz, 8GB RAM, 500GB HDD, Windows 10 Pro) Grade A, Refurbished - Buyfair