Can you live with just one monitor? I can't.
You said USD so no apologies necessary. That said, what size are you looking for? Are there any size restrictions due to space? For example, my desk has a hutch so a 32 inch is out. And if 24-27 inch, it
must have height adjustment that will take it pretty low, but sadly, many monitors don't have that feature.
Also, is a wide viewing angle important? This is typically not that important if you will always be directly in front of the monitor, and you are the only viewer.
Do you need internal speakers? Frankly, in terms of fidelity, no integrated speaker is worth more than Windows system sounds so I look for monitors without them.
Finally, will you ever use this in a multi-monitor setup? If so, pay attention to the bezel width. You don't want a large bezel on the sides if you will be putting two or more monitors side by side.