I know you said budget. If you are looking for accuracy you have to up your game to a White Oak Armament upper or similar. I've built a few with the basic uppers, Palmetto State and similar, and accuracy is usually just a hair over 1MOA. If you want 4 out of 5 at 1/2" at 200yds your are going to need a better barrel. Also, triggers do make a difference. If you want to go budget on a trigger then get the nickel one from Palmetto and then an after market spring kit from Kaw Valley or some other brand and you can get a pretty good trigger at a good cost at 4.5lbs, and sometimes a bit lower. I have a couple of those and they work fine with the inexpensive uppers. Sometimes you get what you pay for.