This is a used product.  The HP ProOne 400 All-in-One is a premium tier-1 business class desktop.  Business-class desktops are better built, use better parts and are often a better option than new low/mid-grade options.

HP ProOne 400 All-in-one

Intel i3-4130T Processor, 4GB RAM, 500GB Hard Drive, DVD-RW, Windows 10 Pro, 6x USB ports, Displayport, Keyboard and Mouse.

Price: $299.99