The graphics card should be the most expensive part (fora gaming pc at least). Make sure you grab a good case, its the most underrated part of a build. Trust me, a full tower or a nice corsair/nzxt/fractal midtower is worth the investment. If you have your budget set, here's how I'd decide my parts...
Build type (mITX, ATX, mATX, etc)
Which CPU company to buy (AMD or Intel)
Motherboard (Which socket type you want)
This may not be everyones opiniom, but this is how I approach all of my builds. On cheaper budgets I'd probably change some stuff up (put psu over case and cpu over mobo)
This post was edited on 1/5 at 1:55 am