Finding a cheap secondary PC monitor is pretty easy. But if you want one that looks good, is built well, and is easily customizable, you won’t find those qualities in a budget screen from a no-name ...
When you think of Thermaltake, the first things that come to mind are probably CPU coolers and PC cases, or even PSUs. You definitely don't think of monitors because, well, it's never made any before.
You should also pay attention to the PCI Express connection–at least PCIe 3.0, preferably PCIe 4.0 or 5.0–and the M.2 form ...