I recently pondered the very question, when it came to advising a family member, who has no expertise in "gunsmithing", no tools, no proper workspace, etc., and ultimately advised ordering a complete rifle from Wilson Combat. The rifle will be pricey, but as near perfect as can be had, of which I was recently reminded, after sending my Wilson upper back to their shop for a reconfiguration of the handguard to add more rail space, etc. It took a little range time and a few rounds of ammo to re-zero the Leupold 1-4x optic (which did not, as hoped, return to zero, after having been removed, then reinstalled on the rail, but the muzzle brake had been replaced in the course of the work, which may have altered the POA/POI relationship...) So, I was concerned that after making the appropriate scope adjustments, and firing three rounds at 100 yards, at a Shoot & C target, I could only find two bullet holes, about a centimeter apart, through the admittedly cheap range rental spotting scope. It was distressing to think that there was a flyer so far out of the group that I could not find it! Eventually a cease fire was called, and I trudged downrange to inspect the target at close range, whereupon I discovered that what had appeared to be only two bullet holes were actually three, one so nearly next the other as to have been indiscernible through the scope. This is the result of the sort of precision combination of barrel, chamber, crown, trigger group, tight tolerances, etc., that you can buy, "over the counter/out of the box", if you're willing to spend the money, and not willing to go through tedious trial-&-error experimentation with a bunch of ultimately mongrel components, with probably inferior results. I don't doubt that one can find rifles of equal ability from other manufacturers, or achieve their equivalent with a DIY build, but considering that "time is money", and that these custom shops have already worked out the trial-&-error issues, they seem like good bets to me.
