Simply going one step down from buying every “halo” product would already do wonders for a significant price/performance increase.
That said, when building a new PC I usually start with the recommendations listed at Logical Increments, which has a neat table sorted by budget. Anything at or above the “Suberb” should give you what you want at 1440p.
I’d also very much recommend a high refresh rate monitor, preferably 1440p, which has either GSYNC or FreeSync with a good variable refresh rate range. It really helps with maintaining a smooth presentation as you aren’t forced to keep your game running at a fixed framerate anymore.
guyrocket