There are two ways to approach this: For $500 a pop you can build a pretty decent desktop with current hardware with warranties for that piece of mind. Or, you can head on to eBay and get something like R730 server for $600-$700 with dual 20 core CPUs and decent amount of RAM. Use Free versions of Citrix Hypervisor or XCP-NG as your OS and deploy as many Windows VMs as you need. Then setup snapshot schedule for each vm for backups, configure RDP, and off you go.

Cisco rv345. Those are cheap used, and give you a ton of customization options in software, and are rack mountable.

My logic is this - if it’s for Linux ISOs only, go ahead and get it; if it’s for backups and important files - brand new is the only acceptable answer. (You can shuck them to save a few $$, but new none the less).