There is an old adage which states, "If you think it helps, it does". I am a firm believer in this philosophy. So if you think spending $2.00 or more, apiece for brass makes you a better shooter, then by all means do so. In 50+ years of shooting, my experience indicates that the case is the lowest member on the totem pole in regard to assembling accurate loads.
Admittedly, the less expensive cases require more prep than perhaps the "premium" cases but since I usually do those kind of things while being dumbed down watching the inane BS on TV, I don't find the prep to be an undue burden.
Case in point is a rifle I built many years ago. It is a 22-308 with a 1-9 twist Shilen Select Match SS barrel. I shoot the Sierra 69 grain bullet and have occasionally kept the 5 shots under 1/4" at 100 yards. Unfortunately, it requires the gods be smiling, or looking the other way or something, because I am really not that good of a shot most of the time. Oh yeah, the brass is RA 70 military brass! Having paid big bucks for premium brass would have been a waste since I cannot do any better.
No, the premium brass would not have allowed me to shoot the small groups more often because when things are going my way, they do, and when not, they don't.