I really don't understand most people's mentality of budgeting for a monitor as an "after-thought", or "whatever is left". I don't want to start a flame war, but a lot of people here spend somewhere between $750-1200 on a full build, probably $200 or more on a GPU that you will upgrade LONG before you upgrade the monitor, and yet you don't want to SEE that performance? you just want to push 120 or 144fps and accept poor colors, contrast, possible dead-pixels and backlight bleeding, and just deal with it for YEARS?
keeping in mind that monitor is on the longer side of most people's upgrade cycle, and that it is an essential part of ANY computer using experience, I would argue that spending $300+, and going for 1440p, or a premium 1080p panel is perfectly reasonable. also, poor backlighting and bad colors are a common source of eye fatigue for computer users. honestly, those extra couple of hundred dollars spent on a monitor is probably very wise IMO